Opera GX is a gaming browser that is very good with the ability to place tabs on the side like Facebook Messenger, Discord, Twitter and Twitch and since im constantly online having it all right in 1 window is pretty op .... due to that bug happening i cant save or load even while ingame (using the phone) so if i want to save my progress i have to leave the browser up until i either find a fix to get back to my previous save or start from the beginning every time
I just installed Opera GX no mods/extensions with feedback etc turned off. So a bare bones install. I am still using Windows 10, it is a bit old and cannot upgrade to Windows 11.
Load/Save of games works fine for me via the icons/links in the left side bar or the options in the phone. The developer console showed no unexpected errors (you will always get some failures loading a few optional js files.
I just played past the initial into until I got Mr. Beasley's paper and no issues it saved. Reran and could load fine.
Can you temporarily disable any mods/extensions for your browser and see if save/load works. Especially anything that can affect page loading or alter page content. Also anything that controls access to browser storage like localStorage, indexDB (theoretically cookies too but no modern browsers allow them)
I have seen one game at the Hypnopics Collective the fails completely if an adblocker is enabled as in-game you can take out advertising and the block could over-react