I was afk for a while, and transform was on when I came back. I do not know what triggers this. However, as you can see in the video, buffs (including potion buffs) remain active after their duration. Tried relogging and it did get rid of it.
I just had this buff as well during zak. My apple and holy shield didn't go away. I didn't have a video recording software up at the moment, but it blinked exactly the same way. I relogged and now it's fine. I don't know how it happened either. Prior to zakum all I did was afk.
I see this issue sometimes for my clients lately. I notice my pets also do not lose any fullness when this bug occurs. I would come back from afk to see that my pets are still out with 100 fullness. I am not sure how to reproduce it but relogging does fix it immediately.