Randomly in online races, usually when someone in the lobby is lagging, all vibrations either reduce to a low setting or completely stop on PS5 and it makes the car extremely difficult to drive. A quick fix is to pause and un-pause the game, bringing back vibrations momentarily until they break again, usually within a lap. An easy fix would be to make vibrations client side if possible to avoid lag breaking them.
This has been happening for the whole of F1 25, but since the 2026 DLC released it seems to have gotten worse. As far as I know this only affects PS5.