Not a glitch, this is intended.
I hate this, every time. I usually go white voodoo and sit back for a few until I can rebuff, but it's annoying if it is intended. I don't see what kind of purpose it serves, and I never had this issue with the skills on PWI, or any other server. But psy isn't my main, so I don't complain about it too much. Just sit back and wait it out.
They're just like invigorate... They go off when switching instances...
It's not between instances. I mean I can be in a battle for 4-5 minutes when my buff goes off, and still have to wait for the skill cd to finish. Also, no, they don't end when you switch instances, so I'm not sure where you got that. o.o They last the entire period, even if you log out of game and back in.