Hello,
once again I tried to replicate, but no luck

(your hero has searched the ruin successfully now)
I have added some extra logging for this game that I will leave on, in case it happens again (seems to be only this game?).
When you searched did you get any response from the server or did you have to make a refresh to see your new xp / level?
Did you move all units there as a stack, or did you meet up there from several locations?
Did you have your units grouped while searching or not?
Just trying to pin down the issue :-/