Hi! Actually, I did almost all the routes and when I do Lawrence's Bad Ending the CG didn't appear too, but O think it's like that?. I left Ray's Routes for last and when I finish the romantic one the picture of Eric glitching appear and his route start without me doing Ray's friendship route, so I saved it.
I think the secret route appears before you end all routes, so you have to play and when he appears just save the game. I don't know if I help but well👐...