yup.
standard with job/case management type systems like this. Super common in IT too.
For example often I would have a call open about some support issue or other with (any number of large technology vendors) re a fix or a bug or something... and often if something wasn't resolved in a short amount of time, the orignal support person (first level, usually) who would retain overall "ownership" of the ticket would often want to close the job even if it wasn't closed but for THEIR stats they want the job closed - even if it meant creating a new one via some other person... because they needed their job resolution counts and timings to meet their SLA's and so on. Meanwhile, as the customer, I'm still like "Yeah, but we haven't actually resolved the issue..."
then we'd have to untangle which case number was "live" vs the originally opened one and then maybe I'd have to explain to some manager or other why they get an email saying the case I opened is closed, but the issue isn't resolved.
yeah.. annoying.
The other thing is when some case management systems automatically create new tickets if emails come in without references or seem different to an existing one, and they're stupid so create a new one. For example, say I put in a request and have a subject like "QFF points not posting".. system allocates a SR (Service Request) number and sometimes can append that SR to the email subject when sending back.. but if I reply to the original one again for some reason, the system thinks it's a new request and aha assigns a new SR.
When I was working 2nd/3rd level support we would often see this that someone would put in a request for something, let's say "QFF points not posting" (and no, I never worked for QFF before people misconstrue this hypothetical example
) which would raise a ticket for that. OK, then a day or so later, they'd write another one, perhaps with the same subject line, but saying "Yesterday I asked about...." and yep.. new SR number. sometimes we'd have the same problem with multiple open tickets and it could get really frustrating (specially when the system would respond back to the first one with a SR attached, and explicit instructions to "reply to this..." but sometimes people wouldn't, and it would get very confused when one has many tickets to deal with, some with similar subject lines, and trying to figure out 3 tickets are actually from the same person about the same thing could be a real time sink).
So there's cynical explanations and just poor case management systems/software that can cause these kinds of things.