+1 to this. It's really a pain to deal with when trying to rearrange large groups of combinators to figure out whether you've broken one of many wires. The mod that preserved wires in 1.1 https://mods.factorio.com/mod/reconnect-cut-wires made pasting fail if it would break a wire connection, maybe ...

I experienced the same issue on 2.0.42 but with different mods. It occurs on the attached save when I perform the following steps:
1. Blueprint a 1-1-1 train, deselecting entities/tiles and selecting only trains.
2. Put the blueprint in my inventory
3. Place the blueprint, waiting for it to be built ...