[0.17.34] Fast and Stack Inserters fail to pick up first item from express underground exit

[EnigmaticAussie]

TL;DR

Fast and Stack Inserters fail to pick up first item from express underground exit

What ?

As the TLDR, placing the below belt/inserter arrangement the stack inserter fails to grab the first item that exits.
If there are more than 1 item in a row (compressed), the inserter will collect the second, and subsequent, items.
Gif showing inconsistency:
https://gfycat.com/InfamousFlusteredCanary

Power is not an issue - I tested this both in a playthrough with 4GW of power to spare, and also creative mod.
I've tested all 4 orientations, they all suffer the same fate.

Expected behavior

I would expect the inserter to grab the first item from the belt.

Additional

Attached is a save game to reproduce behaviour.
Just load, and watch the inserter just below the engineer.

[Rseding91]

Thanks for the report however that's "working as intended" due to inserters chasing items on belts instead of just picking the item up directly. I've been told we aren't going to remove the item chasing so this is the behavior we're left with.

[EnigmaticAussie]

Thanks for the report however that's "working as intended" due to inserters chasing items on belts instead of just picking the item up directly. I've been told we aren't going to remove the item chasing so this is the behavior we're left with.

That doesn't seem consistent with a regular belt.

If I modify the setup slightly:


The inserter will *always* pick up the first, and subsequent items as they pass.

Is there a particular reason that only underground exits are affected?

[tha_snoetje]

Well a normal belt has the whole belt available for pickup,
But an underground belt only a part of it.

So an inserter has less time picking it up from an underground belt.
At least that is what i would assume, and it does make sense.