My "couch/slide" window blind (forward driver side on dual pane acrylic window) pulled free from the horizontal aluminum bar that raises and lowers it. It didn't seem too well anchored to begin with, add some hot temps inside in the summer, and it eventually failed and separated. So, I repaired it by using some 3M VHB 1" wide double sided tape (the stuff folks use to secure solar panels to their roof without drilling holes) on the top edge of the blind to the bottom surface of the raise/lower guide, and it's held just fine ever since. I've got tape leftover to do the other 3 windows if/when they fail.
2018 (2017 Sprinter Cab Chassis) Navion24V + 2016 JKU (sold @ ????)
2016 Sunstar 26HE, V10, 3V, 6 Speed (sold @ 4600 miles)
2002 Roadtrek C190P (sold @ 315,000kms)