I had this issue a once in a steel chest and a few times (4 times or so) in a little different context.

I had a some disabled slots (limited by the red X at the end of the inventory) in one of the cargo wagons of each train, that were meant for unusual item transportation between main base and ...

Bug overview

This bug has 2 variants: either no underground belts are placed, or there are u. belts places but at wrong locations.
The bug happens only if having no underground belts in the inventory, if having a few of them, the placement works.

What did you do? What happened?

Place ...

What did you do?
- have a steel chest with a few items in it
- open this chest in the remote viewer
- [Right-Click] to set remove request on the slot
- [Q] to pick iron plate ghost
- [Left-Click] to remove the remove request and set an item request

What happened?
I had both an active item ...

I think this can cause space platforms to be stuck, see reports 122621 or 119181 about the effects of requesting zero items.

What did you do?
Place rails ghosts. Try to place cargo wagon ghosts over them.

What happened?
Error: "Train ghosts must be built on rails"

What did you expect to happen instead? It might be obvious to you, but do it anyway!
Placing cargo wagon ghosts.

Does it happen always, once, or ...

What did you do?
Tick "Auto request missing construction materials" on the space platform hub logistics and started to build the base.

What happened?
Missing construction materials have been delivered.
But a fulfilled request was not disappearing after a hour, instead a request for 0 materials ...

Clicking through entities.
E.g. when clicking on an assembling machine, the tile (e.g. Dirt 1, Cracked lichen dark) behind the assembling machine will be clicked.

The bug report is about the factoriopedia panel.
I think I also had this issue in other panels in previous factorio releases versions ...

What did you do?

Hover over the items bioflux, yumako, yumako mash, jelly, jellynut in either the player invertory, crafting panel or biochamber
or
view the description in the built-in factoriopedia.

What happened? What did you expect to happen instead?

When hovering over bioflux, yumako or ...