Hello klaumb, this exact scenario happened to me a few times, specifically on the lucky drop bonus game.
As a result I started a screen recording the next time this bonus game was initiated, sure enough the fault happened again. The number I chose should have resulted in a 200x payout but instead a 5x payout was given and in my history the chosen number was different to my actual choice.
The in game live support didn’t even respond the my messages about this so I have approached the casino provider directly with the video recording which clearly shows my choice and what happens in the bonus round and am waiting for a response.
I’m very concerned that this has happened to other customers and they (pragmatic play) have ignored their reports of a fault/issue.
Depending on the response from the provider I may upload the video to youtube - I will keep you updated.