Hi there, this is one of the things I also encountered.
It might mean that the key you sampled into was used before in the sequence. So when you sample another sound into that key, the sequence automatically uses new sample in the same times it was using the old one.
Assuming you remember which samples you used and are not trying to save on any of them here's a longer story:
If you use a key corresponding to previously set "keyboard sample" in your pattern (you use it = it is saved as a part of the pattern) - each time you enter keyboard mode while playing the pattern and change the sample with sample select wheel it allows you to play with the chosen sample but also changes every sequence written with its key it in the pattern. So you get noise and cannot play a keyboard when you used a "keyboard sample" before in the pattern.
I think that's the problem because it was annoying to me too. It still is actually but I'm trying to think if it is important and if anything can be done about it
For me what causes the difficulty is probably choosing a keyboard sample in the pattern preparing process with its number and then turning the wheel seeing the names of the samples along with a red light above the key. Maybe I need to be more focused when preparing a pattern - you need to remember what is where and when it was used. You also have to know what you'd like to do before you start the pattern which is not so easy in the beginning and spoils a little fun when improvising = learning
Hope it will be useful
