Just an update on this, I am using Solus with KDE Plasma, after the week 38 update I am now able to log in to online accounts Google Drive.
This is what the dev said:
Yeah, that working was a side effect of me modifying signon-ui to use qt5-webengine instead of qt5-webkit. Honestly I didn’t even realize it didn’t work before but I’m glad it’s working now. Thanks for noticing that it’s been fixed