Nebula mars II sleep mode switching off in middle of iPlayer

I have recently purchased a Mars II.
We have used it to watch movies and shows on Disney+ without a problem BUT we have tried it a few times with BBC iPlayer and it was shutting off every 15 mins.
We have looked into old posts (from 2018) about this being an issue. The answer it seems is to just turn the sleep mode onto 30 mins and then it is up to me to wiggle the mouse every 25 mins or so to stop it going into sleep mode.
My questions are:
Is there a way other then this to stop it switching to sleep mode?
Why is it an issue at all still?
Is it a fault?

I find it a bit disappointing given the price point that I can’t turn a program on and simply enjoy it uninterrupted. It’s like paying to go to the movies and then, just as you are settling in, the cinema decides to switch the movie off.

My friend, who also has the same nebula mars II, has said this has never been an issue with theirs and where very concerned.