I would take a wider approach to your treatment strategy but stick with the basics.

If something is in a bad position get it in a good position.

If something is not moving get it moving.

Work north and south of the issue.

Use the pistol position as your test retest.

Make sure your talus is moving. Add some posterior distraction to your calf stretching. Uses powerband to distract and gap the surfaces of the ankle.

Address the sliding surfaces. If the skin around your achilles doesn’t move freely over the other tissues with your foot and ankle dirsiflexed you need to break that up.

Smash the shin and foot while you’re at it. Don’t neglect the front of the shin.

Identify your crappy positions. Sitting with your feet up and crossed is comfortable and feels stable but that may be one of your issues.

Since a sport involving running in a hard surface lights it up I’d question foot position as you run. Even if you know what good position is playing sport will keep that out of your conscious and your default program will take over. You’re likely duck foot to some degree as you run pulling your achilles off-center and you’re working on a bone spur in an over tensioned system.

Hope this helps good luck!