Whyd some(not all) sequencer keys in control rig are reset after the project reloaded

So far encountered a problem while saving keys from control rig to sequencer, after project reloaded they are dissapper, I know about saving sequence button and such) the more info about rig: all the control saved have parent constraints on rotation, so most of they have y axis but this one has X, also animationas and pose made with this method saves just perfect, so now the question what is this behavior, its a bug or feature?