I've been using Blender for a few years, and I'm finally delving into making actions for a character. So far so good, until I try to start using the NLA editor - it seems like it should be straightforward on the face of it, but I can't seem to wrap my mind around what it's doing. I'm not trying to do anything complicated - I make the actions with matching start and finish frames anyway, so I don't need it to do any blending for me. I just want to put one action in front of the other, and maybe make a cycle action repeat a few times.
Every single time I try to use the NLA though, it just seems to mess up my actions permanently, in an unpredictable way. Usually, at some point after I have put a few actions in there, messed with repeats and such, then gone back to the dope sheet and tried to make a new action, after using it. Even after deleting all the strips in the stack, one or more of my actions will be permanently altered - random keyframes just seem to get changed somehow, so that I have to completely redo a large portion of the action.
Edit: I also noticed when adding an action into the nla as a strip, it just shows the character standing in rest pose instead, and all the curve channels in the graph editor have red underlines under them...
I have read the official documentation multiple times. It has not illuminated my problem in the slightest.
This is giving me a huge headache and making it impossible to animate my character. Does anyone have any idea what I might be doing wrong?