The picture of bedroom slide shows the slide pulled against the side wall putting pressure on gasket that presses against side wall. If slide is not flush against wall you could get a leak from water moving behind seal as coach rocks going down the road.
A picture of my rubber seal on my slide you will notice what looks like a wiper blade that will travel along the sidewall as slide travels in or out. The blade action of seal will wipe most water off the sidewall as it comes in, the blade has to fit tight against the sidewall with no twists or water will get behind twist and on backside of seal to floor below.
If you have this type of seal a simple way of getting the twist out is run the loop end of awning rod up behind rubber seal so all of the seal will be flush against the slide sidewall outside.
Water will just run off the seal on outside with slide open.
My slide will recess into the wall when closed and put pressure on the bulb part of same seal locking out any water when traveling.
The same seal travels across the top of slide and operates the same way.
This may not be the same as yours but you should have the same response from your seals.
I also lock my slides in when traveling which keeps the slide from moving.