Windows

That seal is just a cosmetic trim piece. Remove it and the glass will still be there. I've had mine out a few times.

If you are worried about it, take it out, start at the bottom to make sure you have a good fit, then work it around so the gap is at the top. Just make sure not to stretch the seal when you put it back in.

You do need to make sure the weep holes aren't clogged though.

Also, the caulking around the outside of the window is more cosmetic and only provides sealing until it shrinks or cracks. The true seal is the putty between the camper and the window. What usually happens is they cut the window opening a bit on the large size so that when the window is put in place, there is very little overlap at the top. When you put the window back in, make sure to shim it up so the window is cengtered in the opening.

x2 on molding being mostly cosmetic, while making backup for glass.
Windows are glued to the frame and glue suppose to make good seal.
I just had my household 4x8' window replaced. Guys used dual-sided neoprene tape to glue the window to frame.

The 'seals' really only hold glass in. Water getting into mounting channel should exit via drain holes to exterior. There shouldn't be any direct path from inside the channel to wall behind the mounting flange. Square windows with corner joints are prone to leaking but full extruded radius windows usually only have a single butt joint, hopefully on a vertical.

The rather large gap in the seal could allow a lot of dirt accumulation but still shouldn't leak, at least into wall.
Looking briefly found this on another forum https://www.sunlineclub.com/forums/f71/how-do-i-fix-shrunken-window-seals-see-photos-17721.html

Are they really seals or just cosmetic? Man, I can't believe the manufacturer would rely on those seals to keep water out. I'd guess they're cosmetic. If you pull the seal out, what's under it?

Scott