ATEM Mini Pro ISO reboots after pluging in a USB-SSD

Hi Community and Support,
I have an ATEM Mini Pro ISO and have used ISO recordings in the past with my Samsung T5 2TB. I know, this one is not supported, but it did work for a year or so. I switched setups and was not using the ATEM Mini a lot.
With the new replay feature I tried to get it working again, updated on 9.5, but neither the T5 nor a brand new (on the supported devices list) Wise Portable SSD 2TB will record all cameras as ISO. PGM record is working fine, but with the option enabled the ATEM is rebooting at least once but most of the time constantly until the drive is unplugged.
I tried:

changing USB-C cables, three are showing the same behaviour

Samsung and Wise, both are resulting in reboots

Switching the streaming profile, no change in behaviour

new format as exFAT of the drives, no difference

I have no idea what else to try and get this working again. Any help is appreciated.

Check the ATEM power supply is the correct one.

If you have an alternative power supply with enough output try that.

Thanks a lot! That helped.