Phew, I came back to my Mac mini today after an uptime of a little over 6 days and it was really bugged out. Apps were mostly failing to launch, just continuously bouncing on the dock and the UI would freeze for a few seconds. Once Firefox opened it seemed to either not be able to access the network or connect extremely slowly as Google wouldn't even load.
I tried a restart and experienced the same results. A shutdown then cold boot seems to have fixed the issue for now, but it even took a few moments to properly launch apps and get a solid network connection but now everything seems to launch quick and load normally.
Currently running 10.14.6 with the 2020-005 patch and T2 firmware 18P50402b.
I bought this as a backup to my hackintosh for work but it's proving to be so much less stable no doubt because of the horrible T2 chip inside. The hackintosh on the other hand is performing beautifully with no errors or crashes and full support for everything I'd want out of Mac. My plan is to update this thing to Big Sur (and skip Catalina entirely as I've only had headaches with that crap OS) so that I can have a fully up to date machine for home use and iOS device management.
EDIT: Spoke too soon. After 10 minutes, it’s back to the stutters bugfest with apps taking forever to launch.
EDIT2: Seems to have been caused by a USB-C dongle from Dell that has VGA, Ethernet and a USB-A port. Compatibility of Type-C devices is all over the place, from what I've read and experienced.