[2.0.21] Train slot request gets sometimes splitted up into multiple requests if train gets outside logistic network

[sben]

What did you do?

Place request in train cargo wagon slot about 50 underground belts.
The train is in automatic mode between main base and outpost.

What happened? What did you expect to happen instead? It might be obvious to you, but do it anyway!

Description of the order of events:
- Robots on the way to fill train cargo wagon slot request
- Train schedule wait condition is fulfilled, train starts moving and leaves logistic network
- Robots give up; no underground belts arrived yet.
- The logistic request got splitted up into multiple requests. Some of the requested amount disappears.

The map displays: 2 entities are missing the material for construction : Missing 7 underground belts. These "two" entities are the same cargo wagon.
Two scenarios when viewing cargo wagon:
- without closing the session:
slot shows: requested 6 items --[clear request]--> requested 6 items --[clear request]--> no request.
- load saved game:
slot shows: requested 6 items --[clear request]--> no request --[close and reopen cargo wagon again]--> requested 1 item --[clear request]--> no request.
So this looks like here are multiple request layers/entries for the same slot. When clearing request in the same session, the '1' item request get cleared first, but when loading save, the '6' items request gets cleared. This is just a theory of me, I cannot test this - but can hardly think of other culprit.

Does it happen always, once, or sometimes?

Sometimes, I had this scenario few times. Could not reproduce if explicitly tried to do so, still happening again.

A save where this happened can be found at (see train at the copper mine, get there using the alert):
https://drive.google.com/drive/folders/ ... OkrRh5SuGY
(I removed the non-Nauvis surfaces with the editor, I can also post the full save if required)

(forgot to secure the log file after this happened, still providing one, since it contains system information that could be useful)