Good Morning:
After you have finished rFactor 2, take a quick look in your Task Manager before you start rFactor 1.
I have had some of our Race Leagues with there members doing same as yourself.
We found after working with those racers , they had a rFactor 2 exe still running even after exiting
there rFactor 2 session.
Once they ended the running rFactor 2 process, There rFactor 1 returned back to
what there had before with there lag/ping.
It might not be what it is, but is worth a look.
Good luck, and report back what you found when you get a moment.
Dave
NRT