I've got two day night shades in my 2013 RLTS that have lost their tension. I assumed the strings broke, and I finally got around this evening to taking a look.
In both cases, the string is not broken. The plastic cord retainers/tensioners are broken. I am attaching a picture of one of the broken retainers.
I inspected a few other shades, and I discovered that most all of the retainers in my camper are cracked. I assume that whoever installed the shades at the factory overtightened those screws. I've found lots of other screws (cabinet hardware, etc.) in this camper that were overtightened at the factory.
So I am on a quest now to replace all of these retainers. I found a two piece retainer that looks like it will be easier to install than my original one piece retainer. I've sent an email to United Shade with a couple of questions about their two piece retainers. Here is link to those retainers...
Cord Retainers | The Dicor Corporation | Official Website
I'll post an update here when I complete this project.