Is there any reason not to contract "yr" after "hoffi"? "Wyt ti'n hoffi'r heddlu?"
You can leave out the contraction if you want to add emphasis.
So this would be used when you wanted to ask 'Do you like THE POLICE?'
My question is more "When it dings me for contracting, should I submit a correction?"
It shouldn't do as we added the contracted form whenever appropriate but if you come across one please do report it.
The actual correction is wrong, hoffi'r is grammatically correct as y is a vowel in the welsh alphabet