Cannot Paste Screen Shots Into Any Application

MacBook Pro 13

After I use my mouse to copy some lines of text, in certain applications, I cannot paste them into MSWord, Gmail, textpad, or other places I'd like to capture the information.

Some .pdf's won't let me use the drag/copy and then paste (I own the Adobe DC).

My school uses UCertify and within the lessons, I used to be able to drag a section of text and copy into MSWord and now this does not work.

Of note, this literally just happened to me this past Monday, July 5th, 2021.

No updates.

I've scanned for viruses and malware.

I've even issued the killall pboard in the terminal (clears out all clipboard activity/history).

I've shutdown all apps and shutdown my laptop.

I've restarted and opened just my school lessons and came up with the same result.

I've restarted and opened just a .pdf and came up with the same result.

Anyone else SUDDENLY running into this issue?

Are there files I can delete and restart my mac?

Thanks for anyone who can help.