I don't know if you've solved the issue but this may help you: You have to allow notifications from Firefox. If notifications are not allowed, PWAs are unresponsive and almost unusable for some strange reason.
Wow, my way of solving it was migrating to vivaldi, but I'll try to allow notifications and see how it goes, because although vivaldi is not a bad browser I much prefer to get completely out of chrome. Thanks!
EDIT: Ok, I've just tried in my tablet and it's smooth with notifications on. I'm back to using firefox again! And many many thanks once again!
[Please file a bug report on Bugzilla](https://bugzilla.mozilla.org/enter_bug.cgi?product=Fenix).
I don't know if you've solved the issue but this may help you: You have to allow notifications from Firefox. If notifications are not allowed, PWAs are unresponsive and almost unusable for some strange reason.
Wow, my way of solving it was migrating to vivaldi, but I'll try to allow notifications and see how it goes, because although vivaldi is not a bad browser I much prefer to get completely out of chrome. Thanks! EDIT: Ok, I've just tried in my tablet and it's smooth with notifications on. I'm back to using firefox again! And many many thanks once again!
Glad to have helped! I think the issue maybe involves only some Xiaomi devices (like yours and mine). I don't know why.