I spawn in 50 second late and sometimes the framerate stutters constantly
I can queue for a game just fine, and the loading screen works, but once I spawn into game its darker than normal and I can't press anything for a ~3 seconds then anything I pressed catches up and the screen goes normal. Once I've spawned I notice that the game has advanced anywhere from 45-50 seconds leaving me in the fountain and my teammates in their lanes. From there the game plays out normally with no issues except for the second bug. This has happened for EVERY game I've played since I've returned from vacation. This happens in summoner's rift, ARAM, and the practice tool.
A second bug happens only occasionally, throughout the game my framerate jumps from <24 to 150 at random every half a second or so. This has happened every time I alt F4 out of loading screen to try to fix the previous bug, and sometimes when I don't. It happens no matter my graphics settings and my computer has been able to run league at a continuous >120 fps before this bug. This bug makes the game barely playable and makes autoattacking accurately impossible.
I've tried uninstalling and reinstalling to no avail, and I've tried messing with graphics settings, but they don't affect the bugs.
EDIT: I updated my graphics drivers and the first bug persists, but I didn't check for the second bug.
EDIT 2: I fixed the issue, here are the steps I took:
>open windows defender security center > go to device security > click on core isolation > turn it off.
Apparently a new windows update trying to fix stuff like spectre and meltdown broke league.