Issue Apache update stuck behind unresolved installation processes?

[fuzzylines]

Trying to update Apache after the 500 error fiasco. I got it to 2.4.49, but can't get to 2.4.51 as is recommended for security. The update (and others) is queued in SSH Terminal:



But I can't pull it up in the Plesk System Updates (saw that updating via terminal is not recommended/supported). I get the "The System Updates tool is already installing updates in automatic mode. Please try later." error when I check for updates:



I'm mostly a noob, but I was able to figure out that this is caused by simultaneous install processes happening at once. By using

ps -aux | grep installer

I see I've got some stuff backed up in the pipes, but no amount of searching told me what this is or what to do about it:



I tried updating Plesk with

plesk installer

That made the above processes go away for a moment and only show the last line in the image, but then they came back.

I used the

sudo add-apt-repository ppa:ondrej/apache2
sudo apt install apache2

commands to revert my site back into working condition after getting the 500 error. Can't figure out if that has anything to do with it and I just need to un-add the repository or what. If it's a problem I can't see anything about removing it.

Any tips on how to resolve whatever is happening here? Am I down the wrong rabbit hole and I don't know it? Thank you very much!