keep forgetting to ask: is it normal to find liquid under the rda (blank) and on top of the mod (topside)?
Happens.
Squonkers rely on the 510 threads to keep the juice from escaping. I will have a small amount under my rdas after a good bit of use. The threads were not intended to control juice flow, just electrical contact. And to be honest not all 510 have a tight fit to prevent juice escaping.
Secondarily how much pressure you put on the bottle can cause this too. Pressing hard will try to force more juice thru than the squonk pin can handle. This can cause what you describe as well as potential internal leakage. Light pressure for a little longer can make a difference.
If it bothers you, you can install an oring on the 510. It will seal the rda and stop the seepage. However the rda will sit noticeably off of the mod.
I chose to pull off my rda after 15-20ml and dry it as sitting flush was more important to me.
Hope this helps.