I love it when I do a fresh fill on the Russian, because the wick gets super saturated and needs to be power vaped. lmao. Yeah, I fill from the top and when it is screwed down the pressure forces juice into the wick, no prob, I just crank it up to 75 watts and have one damn fine vape.
Depending on the gear, filling is where most people either experience some flooding, which has to be cleared, or dry hits, because there was not sufficient time allowed for juice saturation. Also when on the last dregs of juice one can experience either gurgling and some flooding, and also the dreaded dry hits.
The better one knows and understands their gear, the less problems they will tend to have. It's all part of the learning curve. Even experienced vapers have to relearn when going to a new mod and or atomizer. Do a wick or wire change up, and have to learn the characteristics and properties of the new wick fiber and wire.
Vape long and Prosper.!!!