Undo after Erase+encoder push in Step program doesn't bring the previous state

[tnkz76]

1- Open a project and go to Step program
2- Go somewhere that has 2 or 3 events on the same line. Example A1, A3 and B1
3- Press Erase+ the encoder push → events are erased
4- Press Copy+back to undo → Only A3 is back in the above case