Thanks for the help, but I fixed the problem, apparently the GX Corner had problems during the iniciation and the computer thought it was a huge task, so it kept repeating it endlessly, sorry for taking your time
@biskat You can't disable it at the moment. In opera://discards you may be able to turn it off temporarily for the opened tabs you want, but there is no guarantee.
Or, is it https://animedao.to/view/5065365900/? This one plays in Opera after I set PDFs to download at chrome://settings/content/pdfDocuments (which is weird to have to do that). I don't get anything about a sandbox. I have to click the play button in the center of the video area multiple times though to get the video to play. It's almost like the old click-to-activate behavior. But, the video still plays fine, even with Opera's adblocker and tracking protection on.