@sloathe The issue has been found (kind of). I didn't really do any digging into files or anything, but upon looking at my filepath for my OperaGX profile I found that my previous installation of regular Opera from over a year ago was also in the same file path (which makes sense). After just deleting that folder for the Opera classic profile. I was no longer getting the error.
So it's solved, but only has a rough solution of deleting the browser profile data from Opera classic.
Not sure why it became an issue spontaneously, but that apparently fixed it.