Hi Johan,
thanks for submitting your bug report!
Ok, I haven´t heard of this before, seems strange.
According to your description you are doing the steps right, and the display of “Copy” confirms this. It´s correct behaviour that the display shows “Copy” sometimes a little longer, sometimes shorter, that´s not to worry about. I´ve just tried here again and copying tracks works like described above.
Can you store the patterns fine normally? If you just store the whole pattern, I mean?
It´s a prerequisite that the source pattern has content that has been stored there first.
The only thing I can think of right now (and sorry to ask that), but are you sure that the source track contains the right sequence?
Also, have you already tried with different patterns and tracks? Is it always the same behaviour?
Other than that, if all else fails, you could try uploading the firmware again, just to make sure.
Please keep us posted here!