Hello and welcome to the gnome forums.
Automatic language switching introduced in orca 50 can only switch languages with currently loaded speech engine. So for example if you have multiple piper voices you can take advantage of that.
For the next version orca 51 currently in RC stage, automatic language switching has improved greatly by introducing so called voice sets where you can configure preffered engine / voices considered for automatic language switching your-self.
As for your other issue where it’s not possible to switch orca into browse mode on the web, are you getting any feedback when pressing orca+a or are you getting nothing?
If switching can’t be performed orca should report “not in a document”.
Also can you try enabling so called learn mode by pressing orca+h, then pressing orca+a to find out if keyboard commands are working correctly? To exit out of learn mode you can press the escape key.
Also pressing orca+a twice forces the focus mode, pressing orca+a three times forces browse mode in case you are inadvertently locked in the focus mode. By using orca+a again you can unlock it into your prefered mode.
Finally if nothing of this is helpfull as a last resort you might try restarting orca, meaning turning it off by pressing alt+super+s, then waiting a few seconds and turning it back on by pressing alt+super+s again. The super key is just a different name for the windows key.
Also some applications such as web browsers tend to detect if a screen / accessibility support is enabled on launch. So it’s best to make sure the screen reader is already running before launching the web browser or your electron based app for choice.
If nothing of this is still helping then I am not sure but some older versions of chromium and electron have issues detecting accessibility is running. In such a case, can you try starting your browser or electron app from gnome-terminal or alt+f2 run box manually by adding these command line parameters:
--force-renderer-accessibility --enable-caret-browsing
So that might become
chromium --force-renderer-accessibility --enable-caret-browsing
Hopefully some of this is helpfull to you.
Greetings
Peter