Yeah, indeed. I didn't get into the exact same position but still got stuck... the detection if a target position in the grid is valid to be pushed on is incorrectly concluding that the target position is either blocked or not a valid position at all, so the check returns "I can't be pushed in that direction"...
Sometimes you can't approach one of the stones when you come directly on the pathway and have to go sideways, too.
This whole thing is due for a re-write and my approach on doing it fails far too easily...
In my latest test (see screenshot) I got them both stuck and couldn't push them anymore at all, although the flag for being pushable was still enabled (it gets disabled when one of the target positions is reached so once one of them has arrived youn can't push them out of it anymore, which is what I had suspected was happening even though the other one in your case was still too far away to detect the target position and also it should pull itself to the target when it does...)