When doing the hip lift to One legged bridge, I can do the bridge on one side but not the other. Do I stick with the easy not progress the side that can progress?
I would do the difficult side first, and take note of how much time you're able to do. Then go to the easier side and do the same amount of time.
Another option is to change the exercise. Donkey kicks is a progression to the 1-footed glute bridge. So you can try these to get your glutes stronger. Then try the bridges again in a few weeks. You can also do 2-footed bridges too. Hope that helps.