Worker won't swap buckets?

[Brainnagh]

So I have been working on T2 for a while and the most annoying part for me was getting out of the excavator and swapping buckets.

So when I saw there was a worker with mobile wash station specialty for swapping buckets when they are full I decided to hire them. So I hired them, assigned them to the mobile wash station and continued mining, When the bucket got to 100% (there were 7 other buckets nearby) I figured they would swap it out, but it just sat there as I waited and waited and waited. Until eventually I got out of my machine and swapped it myself.

So my question is am I misunderstanding how this all works? Do they only work at certain times of day? Is it a "chance" to swap the bucket and they won't do it all the time?

[Brainnagh]

Ok I figured out what I was doing wrong. So apparently when you have a worker with this trait there is a "snapped" to location right next to the mobile wash plant and you need to put the bucket directly on that spot for them to swap. So it seems I can't just have as many buckets as I want swapping until I run out of buckets and will have to get out every other bucket. A bit disappointing