Apple M6 and M5 Ultra Launch Issues: Troubleshooting Guide

Apple’s announcement of the M6 and M5 Ultra chips has generated significant buzz, but it has also surfaced a wave of real-world problems that users are now grappling with. From confusion over which machine to buy, to compatibility hiccups with existing peripherals, to unexpected performance behaviour on freshly upgraded systems, the Apple Support Community threads are filling up fast. If you’re caught in the middle of an upgrade decision or already dealing with post-purchase headaches, this guide walks through the most common issues tied to the new silicon and how to resolve them.

This is a widespread reported issue, and Apple has not published a single unified fix because the problems span hardware, software, and workflow considerations. What follows is a consolidated troubleshooting path drawn from community reports and hands-on experience with Apple Silicon transitions.

What Causes This Issue

The friction users are experiencing after the M6 and M5 Ultra rollout tends to come from a handful of overlapping causes:

• macOS version mismatches — new silicon typically ships with a build of macOS that isn’t yet available to older Macs, causing sync, iCloud, and Continuity glitches across a mixed-Mac household.
• Rosetta 2 dependencies — some legacy Intel apps behave differently on newer Apple Silicon generations, and a handful stop working entirely as Apple continues to phase out translation layers.
• Thunderbolt 5 controller changes — the M5 Ultra and select M6 configurations use updated Thunderbolt controllers, which don’t always play nicely with older Thunderbolt 3 and 4 docks.
• Unified memory expectations — buyers moving from a 64 GB or 128 GB Intel Mac Pro to an M-series machine sometimes hit workflow ceilings they didn’t anticipate, especially in video and ML pipelines.
• Migration Assistant failures — cross-architecture transfers between older Macs and the new chips occasionally stall or produce broken app installations.
• eGPU deprecation — external GPU support remains absent, which continues to catch users off guard.

Users in the Apple Support Community have also flagged confusion around positioning: the M5 Ultra sitting alongside a newly launched M6 makes purchase decisions unusually complicated, particularly for those weighing a Mac Studio against a future Mac Pro refresh.

Step-by-Step Fixes

1. Confirm your macOS build before troubleshooting anything else. Open the Apple menu, choose About This Mac, and verify you’re on the latest release. New silicon requires the shipping macOS version at minimum. If Software Update shows nothing, restart and check again — Apple sometimes staggers rollouts by region and hardware ID.
2. Rebuild your Thunderbolt chain. Disconnect every dock, hub, and external drive. Boot the Mac cleanly, then reconnect devices one at a time, waiting 30 seconds between each. This isolates the specific accessory causing enumeration failures on the new Thunderbolt 5 controllers.
3. Reset NVRAM equivalents. Apple Silicon Macs don’t use traditional NVRAM resets, but a full shutdown followed by holding the power button until “Loading startup options” appears will let you enter Recovery. From there, run First Aid on your boot volume in Disk Utility.
4. Reinstall problem apps natively. If an app was migrated from an Intel Mac or an older M-series machine, delete it and download a fresh Universal or Apple Silicon–native build directly from the developer. Migrated app bundles frequently retain stale binaries.
5. Rebuild the Spotlight index. Go to System Settings, Siri & Spotlight, Spotlight Privacy. Add your entire startup disk, wait ten seconds, then remove it. Reindexing resolves the sluggish search and Mail behaviour several users have reported immediately after setup.
6. Verify Rosetta 2 is installed. Launch any Intel-only app; macOS should prompt to install Rosetta if needed. If the prompt never appears, open Terminal and run softwareupdate –install-rosetta to force installation.
7. Test with a clean user account. Create a new administrator account in System Settings, Users & Groups, then log in. If the issue disappears, the fault lives inside your primary account’s Library folder — typically a launch agent or preference file carried over during migration.

Additional Solutions

Beyond the core steps, several targeted fixes address specific pain points reported around the M6 and M5 Ultra launch.

For Migration Assistant stalls: abandon wireless migration entirely. Use a Thunderbolt 4 or Thunderbolt 5 cable directly between the two Macs. Wireless transfers of large libraries frequently time out on the new hardware, and community reports show wired transfers completing in a fraction of the time.

For dock and hub incompatibilities: check the manufacturer’s firmware page. Several major dock vendors have pushed Thunderbolt 5 compatibility firmware in the past few months. Applying that firmware from a Mac that already recognises the dock — even an older one — often restores full functionality on the new machine.

For display flicker or blank screens on wake: switch the display cable to a certified Thunderbolt 5 or USB4 cable rather than a passive USB-C cable. Cable quality has become a much bigger factor with the higher bandwidth these chips negotiate.

For pro workflow slowdowns: check whether your primary applications have been updated for the M6 or M5 Ultra specifically. Some professional tools require a point release to schedule work correctly across the new performance and efficiency core layouts. Running an outdated build can leave half your cores idle.

For iCloud sync inconsistencies across a mixed fleet: sign out of iCloud on the new Mac, restart, and sign back in. This forces a fresh token exchange and resolves the majority of cross-device sync problems that appear right after setup.

For Time Machine failures: reformat the backup drive to APFS if it’s still on HFS+. Newer macOS builds increasingly assume APFS backup targets, and legacy HFS+ drives now surface intermittent errors on Apple Silicon.

When to Contact Apple Support

Reach out to Apple directly if you encounter any of the following:

• Kernel panics during or immediately after setup that repeat across clean installs.
• Thunderbolt ports that fail to recognise any device, even known-good cables and drives.
• Fan behaviour that’s constant and loud at idle, which can indicate a sensor or thermal paste issue on new units.
• Display output that fails on Apple’s own Studio Display or Pro Display XDR.
• Battery health readings on new MacBook models showing anything other than 100 percent within the first week.

Book a Genius Bar appointment or start a support chat through the Apple Support app. If you’re within the 14-day return window and something feels fundamentally wrong, don’t hesitate to swap the unit rather than troubleshoot indefinitely.

FAQ

Is the M5 Ultra faster than the M6? In heavily multithreaded and GPU-bound workloads, yes. The M6 leads in single-core performance and efficiency, while the M5 Ultra targets sustained professional workloads with more cores and memory bandwidth.

Will my Intel apps still work? Most will, through Rosetta 2. However, Apple has signalled that Rosetta’s lifespan is limited, so plan migrations for any mission-critical Intel-only software.

Do I need new Thunderbolt cables? Only if you’re running high-bandwidth peripherals or external displays at their maximum specifications. For basic storage and charging, existing cables remain fine.

Can I use an eGPU? No. Apple Silicon still does not support external GPUs, and the M6 and M5 Ultra don’t change that.

Should I wait for the next revision? If your current Mac meets your needs, waiting is always reasonable. But the M6 and M5 Ultra represent meaningful jumps over the M3 and M4 generations, and both are expected to remain current for at least a year.