The spring will rub a corner (strut has four, so there's a lot of opportunity there) and hang (just a bit) before popping loose to hang again and pop loose again.
My old Pre CZ85's strut actually has a washboard looking corners on it. The spring rubbed so many years, so much, that it wore ridges in the corners.
You don't notice it when firing the pistol but if you manually cock it you'll hear it.
You can, as someone suggested, polish those 4 corners to smooth up the spring coils movement up/down the strut.
Make sure your pistol is empty, remove on grip panel, manually cock the hammer and listen to it. Watch it, too. You might see the spring sort of jerk/bounce as the spring is slowly compressed. That'll tell you to polish those four corners on the struck.
Or, as suggested by another poster, it might allow you to see if the spring is rubbing the end of the grip screw on the opposite grip. If not, reinstall the grip panel you removed and take the other one off and cock it to see if the other side is contacting the end of that grip's screw.
Good luck with it.