PC runs fine but taskbar sometimes loads slowly

In all other ways, this PC still runs like a dream. Games load fine, startup is at full average speed, and even this problem in particular isn't 100% of the time, but I've been dealing with it on and off for a year now.

Sometimes I will start my PC like normal, and everything goes as expected, except when I sign in, the "signing in..." Screen takes a little while, maybe 20-30 seconds longer than usual, and then my taskbar icons won't load for a full minute or so.

I can't reliably replicate this issue, but I can reliably fix it by waiting or by restarting or shutting down my PC and turning it right back on. This problem only seems to happen if my PC was off overnight, and like I said, not consistently so. It also seems to happen four or five days in a row when it does happen, then stops happening for weeks. No noticable performance loss during or after.

When I try to open windows settings, I noticed that that, too, takes a while to load when this is happening, and One Drive doesn't start until after the fact. Despite this, things like my start menu work fine, and I can launch software manually without any taskbar icon I'm able to click.

My two leading theories are my One Drive messing something up, or my Nvidia 1060 being too old and buggy to properly load things consistently. It could also be a weird windows process that slows it down.

I suspected a dying CMOS or profile corruption, but I'm suspecting that's not the case because no other symptoms have shown up in this year. Any help would be appreciated!