LED matrix display - MD_Parola, MD_MAX72xx and MD_MAXPanel

hmm mine is more of a constant. There is always 4 lines on the 16th module regardless which module I swap in there and tonight I've swapped them around a few times to confirm. I have seen the effects you mention though, on other parts of the display especially if I hit reset when an animation is in progress. Hopefully I'll get some time to look into it more closely this week.