I only ever use Tubular which, as you say, works fine.
Are you running a VPN? Or a DNS adblock? Maybe the official YouTube app can tell you're doing that (or not running some background Google service) & is trying to punish you?
One other thought: could it be related to hardware acceleration? Is there a setting somewhere where you can turn on/off access to hardware acceleration for certain apps? If so, maybe the official YouTube app had it turned off?