Did a search and couldn't really find a post related to this issue. When in illusion, anytime another player zones into the zone, the player's size resets to default. This happens even before shrinking, as is apparent when you click the OMM illusion clicky (which actually grows you) and when another player zones into the zone your size gets reset to default (shrinks to normal player size.) Also works the other way around, if in illusion and shrunk it'll grow you back to normal size which can be quite annoying in a public zone where you want to remain small. Doesn't appear to happen when not in illusion.
Is this a server or client issue? (UF here) If it's a client issue, meh
