External trim problem

my drivers side exterior, up towards the awnings, between the slides, there is a trim strip about 5" wide. The front few feet have come disconnected from the railing that it clips into.
I've been unable to clip it back in, I think part of the problem is that the plastic is just too old and rigid. I've tried spraying silicon lubricant on the rail and plastic both.
I've tried sliding the trim out as far as I can get it, hoping to reengage the lip, but I can't slide it out far enough.

Anyone ever deal with this trim strip issue?

I do not recall anyone ever mentioning it. Have you called Marathon?

Mark,
I didn't call marathon, i don't find their phone support to be very helpful other than to suggest scheduling time with their service team.
I did solve the problem by breaking off the retainer edge on the back of the plastic strip and glueing it to the aluminum rail.
I tried sliding the plastic off the aluminum rail but that didn't really get me anywhere.
I have a few cracks in that plastic strip which I'm going to spot spray with paint.