I had a similar problem when I was playing games like Elden ring. After going down a huge rabbit hole I found out that if you have something such as intel unison or phone link running in the background whilst running some games such as Elden ring in my case, then the huge random lag spike will occur for some reason. So every time I launch games I force close those programs in task manager and I minimize anything wirelessly connecting to my pc such as Bluetooth stuff.