One of the most overlooked things not taken into consideration with vaping devices is the fact you are dealing with liquids in general. The topvod tank is a nice tank, little upgraded from the subtank line, if it is leaking from the top when you lay it on its side or tilt it upside down, even the most smallest of imperfections in the seal, dynamics of liquids comes into effect, it will find that imperfection, seep through and like all liquids settle at the lowest point it can find. Best advice is if you need to charge your power device in at the bottom, if you can take the tank off and store it upright while the battery is charging, they have what are called 510 atomizer stands, these have a 510 threading in just a base which are relatively inexpensive
$1.23 Aluminum Stand for 510 Atomizers - 7mm(9/32 inch) at FastTech - Worldwide Free Shipping
Just thread the tank into the stand and it will hold the tank upright.
Another fix would be to find seal replacement packs for the tank, the top seal could be just off by a nanometer and cause a problem.
Redneck DIY fix, take an old bottle cap, drill a hole in the center and use it as your tank stand or use a piece of old 2x4 wood and drill some holes in it to use as a display stand.