I also have to lean bike over a lot to get my leg over. My osteoarthritic hip is to blame, many years previously sitting behind a desk no exercise and joints start to lose their movement.
To get more movement in hip joint I have to lay on my back, knees up feet on floor open your knees and just let gravity allow your hip joint to open up. Don't force it, stop if pain's too much. I do this in the bath when warm. You should gradually get more movement in hip joint although don't expect to be doing the splits in a while.
I still have to lean bike over but not quite so much these days (been doing this for 3 years now).
John