Excavator digs ground into a shape that makes it inaccessible to trucks

Issue description

A large excavation with a flat bottom has been dug out. One excavator goes to a corner, starts digging there and ends up being stuck there as the truck assigned to it can't reach it.

This happens quite often, and the solution is to send the excavator to another part of the mine. This time, the excavator goes right back to the corner and gets stuck again.

Expected behavior

Excavator should dig the ground into a shape that keeps it accessible for trucks.

Reproduction steps

• load attached save;
• see attached screenshot which shows where the problem is.

Game version

v0.4.8

Attachments

save_22-08-11_12-49-44 excavator problem.save

Files not imported: save_22-08-11_12-49-44 excavator problem.save

Issue 384, which was ignored by the Developers discusses this issue.
The trucks jump over several yellow tiles and start digging there instead of the closest yellow tile.