@Sephrenia not sure if something has been done regarding this bug but this was a known issue some time back.
See here: Escaped Prison, Still Serving Time in the Outfit (Outfit Lock + Bank Heist Bugs) and see here: outfit bug
Back then at least the Zoi was always changing back into their prison clothes. It would only go away if they Zoi was released from prison normally. As said: not sure if this has been fixed as I have not tried this for a while but at least both bug reports are still open and not marked as solved.