There is a bug in 2.13.1. If I download geocaches using the G4L app (or import just one cache according to a GC code) and choose an existing category that already contains geocaches (while all of them are already shown on the map), then after new geocaches are imported to that category, all other geocaches from it disappear from the map. In Data / Points / (category name), all geocaches are still checked as displayed. After exiting and relaunching Locus, everything is OK.