"
too strong" isn't really something anyone can say. by adding things this you're making PC's stronger generally, and PC's with easy access to expertise even stronger. whether or not its "too strong" depends entirely on your specific table, and how often the DM runs specific types of scenarios, and how high perceptions skills are typically on monsters.

generally what you should consider that this being an ability tied to expertise means that its being specifically given to the people that are most likely to succeed on the check anyway. so while..yeah, there's a check, that by itself may not be as limiting as you think. I do agree with what others have said about being careful not to step on too many toes. I myself have been developing a similar idea for a while but my struggle has been coming up with for bonuses that are fitting, interactive, and most of all...unique.

as a minor notpick, is there a particular reason why you have it grant the invisible condition? hidden and invisible already do the same general things, and the things you put into the ability that would break the invisibility would also tend to break the hidden condition anyway. just seems superfluous as far as i can tell.