I have a similar issue with my left ankle which I’m trying to improve.

Mine is getting better – my top tip is make sure you’re getting your knee outside your foot while mobilising.  I would recommend mobilising the heel bone and the banded calf stretch anterior bias:

I also read that if you’re missing internal rotation at the hip that could cause an impingement in your ankle.  If you’re also getting knee pain I would recommend investigating upstream too.

Another post I saw on this topic with lots of reference videos is: