Important updates to this all here -
Big takeaways I see -
Killing the Gleamtrunks will keep your timer from going back up.
With new hotfix, failing to reach a Gleambow altogether will cause it to go up. 
Low-level players spawn longer timers. I WAS wondering about this, it had crossed my mind maybe that came into play, that those two long timers I had on Xa Frant could have been spawned by low level players.