Hi,
Kinda hard to explain, but loaders are just... weird in 0.18.

Check out this image: https://cdn.discordapp.com/attachments/461234351745794069/670682875883946034/unknown.png

Things I've noticed:
1) The loaders belt seems to be extended out of the loader more than usual
2) You cannot unload or load from some buildings, and can from others - sometimes the same building will load but others wont.
3) Items are being exported out of a box seem to arrive in the next tile over?
4) As the belt is extended past where it should be, you can have some weird looking belts.

After some more testing, it looks like you can only export from a box if the loader is pointing north, and you can only import into a box if you have the loader pointing east.

Hope u can fix it.

After some more reading, the "loader" prototype got replaced with "loader-1x1" for 1x1 loaders, hope this helps.

Okay I've fixed your loaders, you can find the code here:
https://pastebin.com/fmktqXRM

I already know it and I have fix it for K2, but I don't test KL before push it, sorry. Now I have integrate the modification on loaders prototype of K2 in KL.