My M4 Mac mini overheating and freezing after upgrading to macOS 26.1?

To address this question of yours " Does Anyone know what’s happening? "

Also running a M4 Mac Mini with Tahoe 26.1 which does not present of go the issues you have described

Part 1 of 3

Restart the computer in Safe Mode 

Do the issues persist ?

Sometimes a Safe Boot followed by a Normal Boot will just put things right.

If not - there could be something in the main User Account playing up.

To further isolate this - Set up users, guests, and groups on Mac.

Then log out of the Main User account and log into the dummy account and test again if the issue persists.

If the issue is present in the dummy account - then, this appears to be a System Wide issue on the computer.

Part 2 of 3

To Drill Down further and to avoid a session of Q&A, Q&A  and Q&A  

Download the Application Etrecheck  ( External Link ) directly from the Developer.

The Application is Not a " Silver Bullet "  and is  only a tool to examine the Hardware / Software used on this computer 

This is a Diagnostic Tool that makes no changes to the computer Hardware / Software used on this computer 

The application is free or paid from added features. 

The Report will Not Reveal Any Personal Information. 

Post back the Full Report - copy and paste - >>>> using the Additional Text Icon ( 3rd Icon to last ) <<<<

Part 3 of 3

There are 4 Categories of Third Party Software / Services that are not needed 

Get rid of them via the Developers Instruction 

In no special order 

1 - Third Party 2 Way Firewalls 

2 - Commercial VPNs 

3 - Third Party Security Software 

4 - Third Party Disk Cleaners / Optimizer 

Paul Downie wrote:

I have an M4 Mac mini, bought last year: when running macOS 15·x

Or how — bar rolling back to 26·0·1 — to solve this?

[Re-Titled by Moderator]

Original Title: Overheating Mac mini

Rolling Back to Tahoe Tahoe 26.0.1 ?

User Risk Assessment: macOS Downgrade Procedure

Before initiating any downgrade from macOS 26 (Tahoe) to an earlier version , assess the user’s tolerance for potential risks. The following checklist must be completed before proceeding.

Primary System Dependency

Determine whether the affected Mac is the user’s primary or only computer.

If the user cannot function without this system for several days in the event of a failed downgrade, the risk level is high.

The downgrade should be postponed or avoided until proper contingency measures are established.

Availability of a Secondary macOS System

Confirm that the user has access to another Apple computer currently running macOS 15 or macOS 26 (Tahoe).

This secondary system must be capable of performing a Revive or Restore operation on the target Mac’s firmware if required.

Lack of a secondary Mac significantly reduces the ability to recover from firmware corruption or boot failures.

Firmware Compatibility and Secure Enclave Risks

Be aware that upgrading to macOS 26 (Tahoe) likely includes a firmware update affecting the logic board and Secure Enclave Processor (SEP).

Downgrading to an earlier version may introduce firmware mismatch issues, leading to instability or loss of functionality.

There have been at least three documented cases where downgrading from Tahoe to an earlier version resulted in Secure Enclave malfunctions, requiring full system restoration or hardware servicing.

Backup Integrity and Recovery Preparedness

Verify that the user has at least three complete backups created before the macOS 26 (Tahoe) upgrade.

Implement the 3-2-1 Backup Strategy:

3 total copies of essential data

2 different backup methods or storage media

1 copy stored offsite (for protection against natural or human-caused disasters)

Each backup should reside on a dedicated, single-purpose external drive.

For enhanced backup and cloning capabilities beyond Time Machine, refer to:

🔗 https://bombich.com

Recommendation Summary

If the user answers NO to any of the above questions:

Downgrading the Mac is not recommended.

Proceeding without proper contingency plans, verified backups, and recovery tools may result in:

Data loss

Firmware corruption

Secure Enclave failure

Complete system inoperability

See this article.

Keep your Mac laptop within acceptable operating temperatures - Apple Support