I am just now starting to get the same Error Message in Lobby's now as of the last update, but it never happened before that I can remember, at least not as often as every time I go into a lobby like now, it will happen sooner or later.
C1452, did you ever find a solution for yours?
I too have cleared the Cache in both the PS5 and the GT7 side and it is still happening for me...im on Wifi and have a Wifi extender to help, typically have a good signal.
Any help is appreciated, I cannot seem to figure out how to contact PD to ask them what that error means.