Sewage Smell When I run water in sinks?

Hello all, I have a 3 yo house that has had this problem from day one. When I run water in the bathroom sinks, I get a sewer gas smell. It doesn't happen in any other sink or the tubs/showers; just the bathroom sinks. They all have the same size PVC traps. I have private septic which is vented only through the roof (no candy cane vent out on the lawn). I've been thinking the height of the traps in those 4 sinks isn't large enough, but when I compare them to the kitchen sink, which doesn't smell, they are the same. I'm looking for any suggestions - could it be those 4 sinks are tied to their own vent, which may be slightly clogged by a bird/bee's nest or something? Thanks in advance, Bigfoot88.

Are they synthetic tops?

Sorry, not sure what you mean by "top"...

Thanks, Scott

Full size marble vanity tops. Or just a drop in sink.

Corian, I think

As best I can tell they are Corian counter tops with Corian sinks glued on to them underneath.

If they are lav sinks Iwould check the pop up.And try some bleach .

If the sink has an overflow, the overflow can really build mold and smell; so, clean that with bleach, also.