The App needs a Code change. The Code Change, can be found at the GitHubs Issues Page. The question is when will this Patch get folded into the next version, and when will that next version get folded down into the next Flatpak version.
Apparently this Bug, doesn't seem to mind being on Linux, or Windows. Thankfully the Fix, isn't difficult if you know how to read, and know a little CTRL+C & CTRL+V.
In short: Goto: 26.1.9/resources/app/dist/main
Locate the File "main.bundle.js" open that in your Text Editor of choice. Find like 13563 (Using Return to create a new line, and add:
Electron__WEBPACK_IMPORTED_MODULE_6__.app.userAgentFallback = (0,/* .userAgent */ .W)();
Then save it, and exit.