Right-click menu/"My PC" slow after copying files

My Windows 10 64bit PC acts weird after copying/moving a large amount of files (say maybe 75GB or more). I can run my PC for days and it's fine, as long as I don't move/copy lots of large files. I can copy files for a while, but after a certain amount of copying, the right-click menu takes a good 20+ seconds to open. If I right-click any file or folder, the small blue circle just spins while it thinks about it, then finally the right-click menu opens. Also, opening "This PC" takes the same amount of time (20+ seconds) to show the drives with the bar indicating how full it is. And this happens until I reboot.

As soon as I reboot, it's fine again. Right-click menu comes up quick, and explorer works fine, and opening "This PC" instantly shows my drives. But start moving/copying large files again, and suddenly the same thing starts happening again.

This has been happening for a couple years and I can't take it anymore. What can be causing this? I have 16GB memory.

I have Kaspersky free anivirus running but it happens when it's disabled too, and I used to have Avast and the same thing happened then too.

But the right-click thing is only part of the issue - remember, "This PC" is also acting the exact same way, so I don't believe it's specifically a right-click issue - that's just a symptom. When this issues happens, some software also takes longer to open/run - any software that seems to need to detect drives takes longer to run, just like the other tasks I mentioned. It's like after the computer handles some big files or copy tasks, it seems to have a memory issue or something, and the PC doesn't act right again until a reboot.

So don't think of this as a right-click issue - it's a bigger issue than this.

So does this sound like anything anybody in here has encountered before? Something must be affecting my PC in a way that is causing slowdown after copying files. Is it something impacting memory?

- - - Updated - - -

To add, I also notice this can sometimes trigger after I open and close a ton of folders. Just as described above, it's fine for a while, but if I go into a folder with lots of subfolders and open and go back, open and go back, etc. too many times, then the same delay kicks in with the "My PC", right-click menu, detecting drives, etc.

- - - Updated - - -

Nobody has any suggestions for why my PC deteriorates after copying large files?

Your suggestion seemed to ignore most of my original post. What I am dealing with here is not an issue with the right-click menu. Each time I reboot, the right-click menu is fine. It's fine for days straight, without rebooting, as long as I don't copy large files too often before rebooting again. If I do, the computer instantly degrades after a certain point - one minute it's fine, then suddenly it takes 20-30 seconds to detect drives in "My PC", run software that detects drives, and yes, right-click also. And it continues to behave that way until a reboot.
Clearly this is not a simple issue with the right-click menu. I'm sorry, but I'm not going to waste my time troubleshooting right-click issues when it's clear my PC is suffering from something more than that. I already have Shell EX View and I know how to trim the right-click menu down. That's not the issue here.

I'm willing to listen to suggestions, but your suggestion did not fit my scenario.

And I did check indexer backoff. It's enabled, which it is by default, but reading about it, I don't see how that would cause my PC to act the way it does. From what I understand, all that does is control indexing. Indexing is not my problem here.

I thought I remembered hearing something previously about setting too many folder views in "change folder and search options" - something about it leading to memory issues. I do have folder views set to list view for each folder type - maybe that's eating up too much memory?

I also have "Launch Folder Windows in a Separate Process" enabled because it eliminated single windows explorer crashes taking out all my other open windows, but I'm wondering now if that may be part of the issue I'm having, as according to what I've read on it, it can improve stability but can cause performance degradation if you don't have ample memory (I have 16GB, which I thought was enough, but maybe not).