Thank you again for all your replies and suggestions. After trying a thunderbolt gigabit ethernet adapter, I have full 1000Mbps speeds again. I can only assume there was some kind of firmware mess-up with the OS update. At least that won't affect 3rd party hardware.
I can't be sure if any of the suggestions helped the situation, but I learned a few things, and at least I don't have to worry with it now. Thanks again. Cheers!

Maybe you should read your own sources before making unsubstantiated claims. If it had been intentional, using an adapter would not have solved the problem.

[–] baronvonj@lemmy.world 2 points 1 year ago (1 children)

Dude, they disabled a capability of the hardware it shipped with, with a firmware update in the OD update. I have one of the affected Minis. I bought a computer that shipped with gigabit Ethernet and they removed that feature. I don't care if I could buy an external adapter. Would you think it was ok of Nvidia retroactively capped you 120fps GPU at 12fps because you can just buy another GPU?

[–] SimplePhysics@sh.itjust.works 1 points 1 year ago* (last edited 1 year ago) (1 children)

I have a 2012 Mac Mini. It runs gigabit just fine. Might be a firmware bug that they never patched?

Edit: And no, I would not take that from Nvidia. But, I don’t think this is intentional, or else my mini would also be affected.

[–] baronvonj@lemmy.world 1 points 1 year ago (1 children)

I'm genuinely glad for you and the other poster here who got by unscathed. Maybe we have slightly different chipsets. Mine is bcm57766/b57nd60a.

[–] SimplePhysics@sh.itjust.works 1 points 1 year ago (1 children)

I don’t have the actual mini on hand right now, its serving as a home server and I am on vacation. I’ll check when I get back. Btw, what version of OSX/macOS are you running on? I had no problem with Catalina and even Ventura (OpenCore).

[–] baronvonj@lemmy.world 1 points 1 year ago* (last edited 1 year ago) (1 children)

I said goodbye to MacOS after PTP stopped working for Android phones (Photos, Image Capture, Lightroom), and the Android File Transfer (MTP) app broke around the same Mac OS upgrade. I would assume they eventually fixed some of that, but I just don't have any trust left in Apple after all that. My mini is running Windows 10 now, with the bootcamp drivers.

edit: I think Catalina was the last release I had used on it before wiping it for Windows. I definitely went up to Mojave, but pretty sure I tried Catalina too.

[–] SimplePhysics@sh.itjust.works 1 points 1 year ago (1 children)

Ah, alright. Does gigabit work for you in windows? If it doesn’t, you can try installing Catalina and updating the Bootcamp drivers.

[–] baronvonj@lemmy.world 1 points 1 year ago

Does gigabit work for you in windows?

Unfortunately no, hence why I suspect it was a firmware update, not just a driver bug.

If it doesn’t, you can try installing Catalina and updating the Bootcamp drivers.

maybe. but I wouldn't want to deal with messing with bootloaders again if it breaks my Windows install.