I was tidying up my schematic by moving the blocks around and after doing so some of the nets were errored. Looking closely I could see several cases where a horizontal wire abutting onto a vertical wire had lost its red dot and the horizontal wire ended just a small fraction of a grid square away from the vertical wire. This really shouldn't happen when moving things.
Electron
4.2.10
Windows
10
EasyEDA
6.4.25