If your fix is unreliable you may need another way to get in. You maybe haven't found the root cause for the failure.
"March 20 and it worked fine until a few days ago."
Let's say the original fix worked for 10 weeks so this needs to work 30 consecutive weeks to be reasonably sure you nailed it.
But I'd expect subsequent fixes to work less well do to wear. You've bought yourself some time so I'd go looking for a drawing on this hidden mechanism. You need an as-yet-unidentified part.