We're talking about a 2018 Silverado with the max tow options here.
The receiver is not fastened to the bumper - at least it is not on my 2017.
The truck has towing capacity of 11 000 lb and payload will be around 1900 lb. This is fine for that trailer.
I have found some stretches of highway cause porposing due to the harmonics set up by the spacing of the expansion joints. The only solution I know of is to slow down until you finish with that stretch.
Items that have helped:
ensure WD hitch is correctly set up to transfer load back to front end. I have Equalizer 1400 lb bars for tongue that is 1200lb. Hitch head needs to be tilted enogh to bring front of TV back down. Bars must be parallel to the trailer tongue and they should rub evenly on the L bracket.
I did not like the OEM shocks so I put Bilstiens on after about 6000 km. The truck rode much better.
Those are my suggestions from using a similar truck towing a similar sized trailer. Last winter we went 11 000 miles with that combination.