What's the difference between the two invite to toilet scenes? I found the one with the guy not too far left from the bathroom, but not the second one
I believe the 2nd toilet scene can only take place after clearing the events of the NTR route (the two bottles, the 1st invite to toilet by the pillar, the balcony, the hotel, and the pool). You get an email on Saturday morning (after telling the brother that you're going out alone) about somebody waiting for you in the cosplay venue restroom, and once excitement is high enough you can find an EV outside the restrooms on the far southeast area.
The event condition checker seems to confuse the two events and gives a misleading response about the 2nd event being ready when it's not--it needs to be triggered by the email before leaving for the venue. You can tell you have the right event because there's a group of guys for the 2nd one, rather than just the one guy (by the pillar) for the 1st.