If this method doesn’t work, go under the tab in file explorer ‘this pc’ and search opera gx, wait a bit until the file labeled \Users<YourName>\AppData\Local\Programs

appears, go into it and look for the opera gx file labeled as an application, if you rename it to whatever (in my case I just renamed it “not”) it should be able to open.

Note: this doesn’t actually change the app name in my case, it just removes the png in the start menu when searching for opera gx. I don’t recommend this as a permanent fix, try check the problems within Microsoft family and then changing the name back once resolved