Update: Issue Resolved
Turns out i had entered my birth year wrongly in the google account, on the day when i tried to login, i was of 101 yrs old,
if the logged in user, turns 101, you tube disables the ‘toggle’ switch it seems !
when fixed the birth year, the issues resolved 
Description of the issue:
recently i did a fresh (re)install of brave with new profile configured just for you tube.
an issues observed with the auto play toggle visibility,
-
when i haven’t signed in with my account → i could see the auto play toggle & i can make it on or off
-
as soon as i signed in to my account → the toggle control is gone, but the videos are playing one after another, hence i don’t have the option to stop it!
How can this issue be reproduced?
-
install latest brave browser in win 11 machine
-
create a new profile
-
launch you tube & play any video → the auto paly toggle control would be available
-
signing with an you tube account → the auto play toggle control is gone
Expected result:
the auto play toggle/button/control shd be enabled/available always
Brave Version( check About Brave):
Version 1.65.123 Chromium: 124.0.6367.91 (Official Build) (64-bit)
Additional Information:
-
didn’t have any extension installed
-
tried with incognito mode → same outcome
-
tried with site data clean → same outcome
-
tried with complete history cleaning along with site data, cookies, cache etc. → same outcome
-
tried with brave shield disabled → same outcome
-
tried with creating new profile → same outcome
-
till few days back, i was using the you tube in the same way, it was working as expected, due to some reason, have to do a clean re-install & then this broken controls i see
-
tried checking some config on you tube side as well - don’t seems to have any setting/config creating this behavior