Weird smart belt behaviour, and it's inconsistent with planner

[Yuki_Nagato]

Behaviours with smart belt is better describled with a video:

Factorio - 2025-06-02 13-48-16.mp4

(229.62 MiB) Downloaded 24 times

There are three situations:
1. red belt, without red underground belt in inventory;
2. red belt, with red underground belt in inventory;
3. green belt without green underground belt in inventory and without green belt.

[Loewchen]

Describe what you consider to be the bug please and add the version to the title, see 3638.