[SOLVED]
Turns out I'm just a bigger moron than I thought. The MAC address of my server had accidentally been flagged in my router for black listing.
As the title says, my proxmox host is apparently not able to reach the internet anymore, not sure for how long this has been an issue, I rarely work on the host itself. It can ping other devices on my network just fine, and other devices can ping it. I can also SSH in to it and access the web interface. My VMs are connected to the internet without any issues. I don't need to access the host remotely/outside my home network, this is just for updating it etc.
I can't see the host under active devices in my router though.
I have been trying to figure why, but so far without any luck.
Technically the only thing you're allowed to fiddle with, while driving, is what you can operate from the steering wheel. You're not supposed to fiddle with radio, AC etc. from the center console while driving even if it's physical buttons.
I know people don't drive like this, but you're only allowed to take your hands off the steering wheel for changing gears if driving a manual, otherwise it's two hands on there at all times...technically