The Composer, reoccurring bugs isn't uncommon in video games. This can happen several different ways. Quite a bit of time can go by while a game is working fine and has no problems with a particular bug, only to have it reappear the exact same way.
One way is program collection. Programs are typically tested is separate pieces to speed testing. Then someone compiles everything together into one package. (For the record, I have done this exact job before in a tech company.) However, if someone is using the incorrect version of a chunk of code being tested, it will test fine for them and it gets wrapped up in the entire program. When I did put the composite together, I only had a couple people feeding me code, so it was easy to figure out when something like this happened. With larger code pieces this requires more people and would be a pain to track down.
Another way bugs reoccur in games is that the bug doesn't actually get a fix, but gets a work around. When the code gets updated in the future, more code is added that circumvents the work around and you see the bug again.
Miscommunication can arise as people move on to different jobs within a company. If the new person working with the code believes that the wrong version of code is working and the correct version is bugged, a bug returns.
I'm certain there are many more relatively simple ways that cause bugs to reoccur. As such, the time when current instance of the bug is noticed is quite relevant as you can go quiet a while with everything working fine before the bug occurs again.