It's not just you.
It has indeed been discussed before, but I don't think it's come up recently.
Personally, I use a really ugly hack to hold it in place by force.
I took a piece of wood roughly as long as the back of the instrument is wide, and just thick enough to do the job.
Then I took the kind of plastic mount a plumber would use to hold a pipe in place, and screwed that into the middle of the flat side of the wood.
Holding that against the back of the bass, I swivelled the endpin down so that it's sitting in the mount, then wrapped a small cargo-strap around the whole thing, including the bass, just under the bridge.
Hopefully these pictures get the full idea across:
View attachment 3909142
View attachment 3909143
The grey oval-shaped thing is a sticky sheet of rubber, that adds a bit of friction to hold the wood in place more firmly. I think it was designed to stop sliding sunglasses around on the dashboard of a car.
(I
said it was ugly)