for reference BDSat-2.
difference between stations can be in the tens of seconds, I noticed when I worked on the geoscan-edelveis image decoding. iirc mostly in the 10-30s range but up to a minute sometimes. I would guess that 5-10s is too low, 30-60s would probably de-duplicate almost all such occurrences.
maybe raise an issue in db to solve it on a higher level ?