Around 15-20 mins in my game on the new SR the HP bars of almost all of the jungle creeps, minions and the inhibitors began to glitch.
The minions and jungle monsters displayed no change in HP after this point and would always display 100% of their HP although they would still die after the appropriate damage and time it would take to kill them.
Both the inhibitors and nexus also had the exact same HP bar problems. Apart from this, both displayed un-targetable signs when I hovered my cursor above them (even if they should have been targetable due to their required objectives). I was a Corki (ranged) but in order to attack these structures I had to move into melee range to attack them.
List of all things that I encountered HP bar problems with:
Blue Buff camp
Red Buff camp
Fat chubby monster (can't remember his name lol)
I wasn't able to test Golems and Baron but I assume the problem was with all jungle monsters.