Digger heads not moving forward with the rest of the digtron

[qwrwed]

This has happened to me a couple of times so far. All nodes move forward except for the digger heads at the front, causing the metadata of the nodes directly behind the heads to be transferred to the heads while the actual nodes in question are destroyed. I can then access the inventory/data from the heads themselves (see screenshot).
The second time this happened I noticed that I had left the digtron to go on ahead without me, so possibly related to #35.

Update:
It's now happened while standing on the digtron as it moves, no blocks were destroyed but the inventories and the floating icon indicators for the builders were all pushed forward by one, glitching out the whole thing again.

[FaceDeer]

This is yet another manifestation of a subtle bug in Minetest that's causing Digtron to not be able to write all of the node metadata it's trying to. :(

Fortunately, I think the end of this long-running problem are in sight. I have finally bitten the bullet and started a complete rewrite of Digtron from the ground up, the DIGTRON 2.0 project. You can follow its progress here, though at the moment it's still a bit embryonic.

Digtron was actually my very first Minetest mod, way back in the day, and it shows. The foundations are poorly designed and patching it is no longer sufficient. I think this new approach is going to work much better.