Confirmed. With Stage Manager turned off, when viewing a camera or camera group, you cannot get out of landscape without physically rotating the iPad or force quitting the app. However, on the plus side, if you turn on Stage Manager, you now have full “normal” functionality with the iPad in landscape mode. Granted, the home page of the app is still portrait view displayed on the landscape iPad, but at least you’re not reading sideways. Whether getting stuck in landscape camera view is considered a bug or not, I don’t know since we got improved function with SM turned on.
See my post here: Landscape View For Tablets - #914
Also confirmed that the rotate button 
in the upper right corner seems to flip you to a static image from a previous time/date. That would definitely be a bug.
I will get this all reported to Wyze.