I saw this too and panicked! I saw the sea of red on the StorjNet site and thought my server or connection had gone down. Neither of them had.
Seeing these updates was a relief, my version is now the latest (v0.19) and I too am also seeing the same as posted here: Pq: duplicate key value violates unique constraint \"used_serials_pkey\" (after upgrade to v0.19.0)
Last contact time is always sub 1s so based on the information here I’m happy for now!