Update 24H2 leading to repeated crashes/restarts

Hello,

On the 4th of Feb, I updated my laptop to 24H2. After an uncommonly slow update process, I tried to use it, only to find that the laptop was force-restarting itself at most 30 seconds after logging in (more precisely, 30 seconds after the log-in screen appeared - it did so even if I left it without logging in). It was also very slow and laggy until the restarts, especially with bringing up the taskbar. The problem was fixed when I uninstalled the latest feature update, and I tried again today with the same results.

Further info: The first time I tried to log-in I got a ToS agreement pop-up from nVidia broadcast, though the issue persisted whether I agreed (on Tuesday) or rejected it (today). Further, from the couple of times Task Manager managed to load fully before a restart, I think various nVidia programs did seem to be taking up 100% of the CPU, which I presume would explain the lag. 

Probably irrelevant information: the router has been getting somewhat confused about its IP address, making my anti-virus software repeatedly grumble about cache poisoning, but I doubt that is related.

Some system information: I have both an AMD Radeon 780M and an nVidia GeForce 4050 Laptop GPU, and the processor is an AMD Ryzen 7 7840HS with 16GB RAM.