Hey Schallfalke. I notice a bug while using Deadlock beltboxes for compressing and decompressing stacks. At first I thought it was Deadlock so I did some digging. I found when deadlock sets the beltbox speed he uses the following:
crafting_speed = data.raw["transport-belt"][tier_table.transport_belt].speed * 32
I checked what you had in data-updates and it is the following:
if settings.startup["deadlock-enable-beltboxes"].value then
dr["furnace"]["transport-belt-beltbox"].crafting_speed = speed_T1 * 18
dr["furnace"]["fast-transport-belt-beltbox"].crafting_speed = speed_T2 * 18
dr["furnace"]["express-transport-belt-beltbox"].crafting_speed = speed_T3 * 18
end
I changed the value from 18 to 32 and it works seamlessly. Could you please make an update to your mod to update the same value as Deadlock please.

Alright, probably Deadlock changed settings in some recent versions.
I will investigate and update that, when I have time.

Just released 0.17.5 including these changes.
The problem originates from changes in Deadlock beltboxes version 2.1.12 that I am unaware of.

Thank you! You do great work and you always reply!

You are welcomed.

And I realize that I have slowly made lots of mod (currently 33), that I cannot be vigilant to all the fine details.
Users like you really help me a lot!