[2021] 1.31.5 lag spikes in late games

If you revert to a previous game version that used to run alright for you, does it still? Or does it have this problem too now?  

I was going to suggest you lodge this as a bug report in that forum, as it now reads like a code problem (on your machine at least).

However I missed that you are in Win11, which is of course only in beta at present and so unsupported. You are still welcome to make that bug report though ! Can't hurt, might help.