This is the only answer i can find and, sadly, it seems to be correct. I find auto play the most annoying when i want to leave a comment at the end of the video and get cut off mid writing. If people want bad features, they should be optional.
This is an important feature and should absolutely be easy to implement. Autoplay is generally terrible and it's currently default with no way of turning it off? Come on, Rumble! Step up the features here.
After the video you're watching has ended and while the next video in "autoplay" mode, is loading, underneath it you should see the word CANCEL. Just click on that and it will stop the auto play and give you 6 choices of other videos to look at that are static frames in the playback window. It won't disable the auto play but at least you can stop it so you can write comments on the video you just watched without it cutting you off in mid sentence. Hope that helps.