Scribbling does not work when selection includes alignment start

1. Open file "test/_common_data/scenarios/msa/ma.aln"
2. Select some region starting from the 1st column and ending in the 8th one
3. Drag it to the right in one column
4. Click left mouse button in the leftmost side of the selected region
Expected state: the region should move back to its initial position
Current state: nothing happens