I may have misspoke, I use an AUR helper to install many programs and utilities, and am not at my computer to view the actual source. So I took a gamble and guessed AUR. My apologies.
It could have been other instability, as I mentioned in another comment I didn’t really look too deep into it since it wasn’t so important. And by no means am I blaming Thunderbird (regardless of source) for the issues I have had. It truly is a great email client.
Edit: It is from official source, not AUR. I have the same setup on my personal laptop. It came from Extras, and not AUR.
May have to investigate a bit. May have to figure out each directory to purge, do a pacman -Rnsu thunderbird