PSA: confirm your earning preference to avoid surprise.

After a recent stay at a Marriott property, I noticed I was credited with United miles, not Marriott points. I have United MP # there due to RewardsPlus.

I find it irritating that I did not change any preference setting in my profile by myself - my prior stay was correctly credited with points - and that the value of miles (1x room rate) is significantly lower than points (15x room rate as Platinum)

Anyway I can ask the hotel or Marriott to investigate who made the change without my knowledge (e.g. hotel front desk?) and credit points instead?

Thank you!