These looked like black ants with evenly proportioned bodies, (I've since learned they're not ants but ant-mimicking flies)! Photos 4 & 5 are for context.
@MazzV the wings are transparent but you can see the black dot on each wingtip in your photo quite clearly even though the photo quality is not ideal. Hereβs a link for you to scroll through so you can see what I seeπ https://www.inaturalist.org/taxa/522266-Parapalaeosepsis-plebeia
@DiBickers as soon as I read about the black wing dots I went back and saw them! Wonderful, and great info at link. A mistake I can now avoid, TY MazzV