From patch notes:
"Adjusted the duration for all Immovable potions. The base duration has been reduced from a cap of 12.5 seconds to 8 seconds, leading to a Medicinal Use maximum of 10.4 seconds."
So why on live immovable effect of cp 150 potion with Medicinal Use lasts 5.7s? Its not the Medicinal Use fault as other effects like magicka regeneration are lasting like they used to ~46s.
"We are currently investigating connection issues some players are having on the European megaservers. We will update as new information becomes available."
— They always claim they’re “investigating” the causes, but in reality they’re just waiting until the PC EU players go to bed. Once that happens, you can suddenly log in again and they happily mark the issue as Fixed.