You and thousands more with the same complaints
These topics are covered in great detail on the RV Forums>chassis club>Ford chassis. Topics of interest for you will be: CHF (Cheap Handling Fix), rear track bars, steering stabilizers, springs and shocks.
Literally THOUSANDS of threads in hundreds of posts. You've got a lot of reading in front of you. What you are experiencing is curable.
Randy & Karin B, Portage, MI
2017 Newmar Ventana LE 4037 & 2021 Chevy Trailblazer