Hay Jonathan!

Following ankle instability it is very common for clients to get knee pain. This can be due to a number of factors. It would probably be highly beneficial to go see your local physio to get this assessed. However, If you are after more help on here, can you also post a front, side, front and to the left (so we can see the inside of your foot while standing normally, and also front and side when standing on one leg. I know this is a lot of photos, but would give us a lot more to go on.

Also, can you include your foot and knee in these photos? And describe some more symptoms of your pain, location, intensity, type, duration of onset, aggravating factors, do you notice any differences between the two knees? What are your current shoes like, any orthotics? Try and give us as much information to correctly diagnose you.

If you go to see a physio, let us know what he diagnoses and we can give advice on any exercise prescription / ideas for your rehab.

Regards,
Musculoman.
Additional Comment I forgot:
Here is an article on chronic ankle instability which might help you get a good idea of what is likely going on in your ankle.

Functional Anatomy, Pathomechanics, and Pathophysiology of Lateral Ankle Instability

" Functional instability is driven by insufficiencies in proprioception, neuromuscular control, postural control, and strength "

Taken from the article, these deficits can also lead to poor knee mechanics/control/loading patterns/muscle activation patterns etc. in the knee. Have a read and get back to us on some of those questions I asked, and we will see what we can do!