I notice some are having connection problems there are a couple of things you can try but with iRacing I have found I had a different problem with my connection.
My ping is fine and connection good 100mb down 10mb up only me using, my problem was in races with large fields I had noticeable input lag, I run nothing wireless apart from a few IOT switches for lights etc.
First tip if possible a lan cable connection from router to PC is preferable particularly if you are in a high density neighbourhood.
Second tip that solved my problem in some sessions giving me a noticeable time benefit by removing input lag was setting my connection type to lowest availablle on my account page, I believe ADSL 128k.
My downloads are still rapid & going from practice to race session I usually arrive/load first which was not the case before I reduced setting from top connection 2MB or better to lowest 128k.
Running for a month on that setting I am seeing zero downside to the change, but I have no severe lag any more, I had tried to solve with iRacing techies & my ISP in past it used to be very bad in Races & Time Trial sessions even when running DMZ config no protection firewall or virus protection.
Something worth trying for all, it was US servers that were worst for me so it may be only Europe/Aus etc that are affected by this but worth trying.
I saw laptime improvements on track from day 1 which could just be something had clicked in my brain, but I now have same acceleration as others, which is where my lag appeared most prominent I have made no other changes at my end.