I have a flash 5 1. I have been using high sierra for a while. Starting with 10.13.4 and now with 10.13.5, I have this weird graphic's glitch on the login screen. The login screen looks grabbled. It's hard to explain. After login everything is fine. This happens with multiple gpu (gtx 650, gtx750 and gt120). Anyone else have this issue? This also happens with or without nvidia webdrivers.