Greetings.
In most recent update I had to make myself familiar with medicine system.
This was the first time I used it, os it might be just me being not familiar with system.
In any case - what happened that colony was raided and fight happened.
After the fight one of colonists was delivered to medical bay for treatment.
Inspecting the colonist revealed that he lost his left leg.
Wood was ordered and peg leg was installed.
However, after a week, colonist still remained in a medical bay.
His health overview shown that he is unable to walk, at all.
I decided to remove his healthy leg and place a peg leg instead of it, thinking that he might be afraid of asymetry.
After operation he was able to walk, according to health overview, but he never actually got up from bed and after a day he regained inability to walk.
I gave up on him and just harvested some organs.
A few days later I was raded again and one of my colonists lost his foot.
As he was unable to walk, peg leg was installed and whole story repeated again.
Savegame or it didnt happen :D
I abandoned that colony already since ice sheet biome clearly is not quite polished yet, no savegame present.
His walking can be affected by lots of things, including sickness, bad back, etc. Just having legs doesn't mean you can walk. So I think it's not a bug, without a real repro.