Tape is suddenly in other slot

Is it possible that a tape will be moved automaticly from 1 slot to another free slot?

For example, we insert on friday 6 tapes in slot 1,2,4,5,6,7. There is a clean tape in slot8 and slot 3 is empty. 1 and 2 contains Diff tapes and the rest is full.

On monday we find the tape in slot 7 to be in slot 3. For as far as I can see there is nothing to be found in the logs of BE. Just the import on friday.

Can the software do this by itself?

Thanks.

Marcel