The floating ball setting on the phone is gray and cannot be opened
The reason why the floating ball setting on the phone is gray and cannot be opened is that TalkBack with accessible vision is enabled.
You can turn off TalkBack by going to [Settings] >> [Additional settings] >> [Accessibility] >> [Vision] >> [TalkBack] >> toggle the switch.
You can turn off TalkBack by going to [Settings] >> [Additional settings] >> [Accessibility] >> [Vision] >> [TalkBack] >> toggle the switch.
Does it help?
Yes
No