If you're on Hard or Extra Hard you should be able to get higher point gains of you're solving quickly enough.
However, if your Puzzle rating is a lot higher than your game ratings, your average puzzle ratings will be lower and you may not get many higher rated puzzles
It's not a bug but part of the new puzzle design. There are a few upcoming updates that will show the actual ratings being used in the UI
So when ever i complete a puzzle right i gain 5 elo and if i get it wrong i loose like 25 i tried difficutlie change and it didnt change much...
Idk at this point why but it is making it really hard to increase my rating i do like 20 puzzles a day and hardly increase because of the +5 i feel like stanrdard should get +10 hard +20 and extra hard +35
and loose the same