99% (sometimes for some reason it connects correctly, related to order of placement?) of the loaders that connect from belt to an entitity with inventory when placing a blueprint in /editor mode don't get connected to said entity. They have to be manually removed and placed again to fix it. To reproduce just make a chest -> loader -> belt -> loader -> chest blueprint and place it in /editor mode.
Ohh hmm, people have been mentioning this behavior for a while but I've never been able to reproduce it - I guess editor mode is the key, because yup, that's messed up. Will see if I can work out a fix.
Now that I look at it, I think this is just editor mode's fault (or more specifically its instant blueprint building setting); it's just creating the entities as if they were directly dropped by a player, instead of creating blueprint entities and showing some indication that it was a blueprint build or revive in the event. Are you seeing this anywhere outside of editor mode?
I think we had similar snapping issues on our community map when filling ghosts when a loader was placed before a chest it went to. This may be on picker tools though because we had the option that automatically places on top of ghosts when hovering with an item enabled. If this is editor's fault then it maybe warrants a base game bug report.
Picker Tools has had all kinds of unpleasant interactions with the loader snapping in DSB in the past. There are hard limits on how much you can proof a mod against interference from other mods.