We also have the day/night shades and they also were VERY tight from
the factory. Most were super hard to move and a couple nearly impossible.
Way back 4 years ago there was some discussion about this problem and
someone who said they installed and repaired these type shades wrote
in and said-- "the most common problem with these shades is they are
installed with the strings too tight".
With that little gem of info I proceeded to loosen all the strings on all
my shades and for the last 4 years they have been fine. We don't have
a problem raising and lowering them and they stay put.
Donno why the factory insists on putting them in so tight. I can only guess
it's because they install them and then don't actually camp and use them
to see how they work in the real world.
On some of mine I was able to untie the knots and get the little bit of
extra string I needed. On others I had to move the anchor screw up
slightly to get the the needed slack but they all work great now.
Much like the OP we didn't know how good they could work at first
because we'd had no experience with them before.