Android device won't sync.

No matter what I do, sometimes, Firefox on my phone won't sync and it's driving me crazy to be honest. I don't know why it happens, it has no fixed schedule and it seems to go away on it's own in a seemingly random amount of time. In this instance, as I'm writing this I've been trying to sync with my PC for over an hour and it simply refuses to sync. I've tried restarting, force stoping , clearing cache.. Nothing. In the past I even tried reinstalling and for it to sync it took a while. I'm lost with this bug and it's been happening for a while now, I was hoping for a fix but so far it seems it hasn't come.

Please let me know if additional information is needed.