Monsters getting stuck and killing me

I've been questing in Central Thanalan lately, and this has happened on a couple of quests now (In the Court of the Rat King and The Threat of Paucity so far) and even basic hunter log tasks. But what happens a creature will be unable to move, essentially stuck, but is still animate. At which point my spells no longer do any damage, but they can still do short range attacks to me no matter how far I go (even in Sanctuaries). Sometimes my potions don't even heal me when this happens. So far this as happened with Qiqirn Shellsweepers, Sun Bats, Efts and Orobans. Sometimes I can get away and fight a different monster than listed above (Hammer Beaks have worked) and the problem corrects itself. But if I can't, then once I die it seems it takes a long time to load up my restart point in Ul'Dah (way longer than usual). Then shortly before it does load the screen says "Cannot execute at this time" in red letters several times before I and Ul'dah appear again. Any fix or solution would be appreciated. Thanks.