From my experiences, the bubbles just disappear without any residue or other signs of problems.
My belief is that this occurs especially to tight mtl vapers. Since there is more vacuum, if there’s any vaper left over in the chamber, it is sucked into the tank. This is definitely more visible on the tripod, since there’s very little space between the glass and chamber
Thanks @ZenAnarchi. Here are some pics after using SLIVR - I used it for a while then experimented with the Nature Vape stuff. There is still a milky bubble and it bursts with the same kind of "mist".