All wired devices on the network (except for an AP strangely enough) drop all connections and can't get DNS responses.
I haven't had the time to dig in further than that yet though.
Someone did reply with this link[0], which may be the same or similar to what I'm experiencing just a different scenario.
[0]: https://mjtsai.com/blog/2022/05/11/usb-c-hubs-breaking-ether...
Turned out that it happened when one specific USB-C dongle with ethernet and PD was left powered on but not connected to the computer (I think there were other preconditions as well like it was powered-off and you connect power to it but not a computer to it). The device will then decide to go into DHCP server mode and start sending advertisement packets and the switch would start broadcasting them, the internal firewall would see this and start blocking the switch and in turn turn off the AP that was connected to it so 26 ports would be offline essentially. Most of us were on wifi and everyone who was on an ethernet (3 ppl) would go "FFS internet is unstable again. Stupid switch is probably buggy", disconnect their cable and go on wifi. Plus they never really reported it as they had work to do and Wifi kinda worked so not a big issue.
It was just a really cool moment when we found out what caused it and we fired up Wireshark and looked at the traffic and we were right. I haven't had a moment of so much joy in a really long time.