.01 .03 off is ok but .3 no still not right
Try another tank and report back
Good luck
Actually on above 1ohm coils, it is not uncommon for Kanger and other Premade coils to read +/- .2ohm. Obviously you do not want this in a Sub ohm coil, but it is still a manufacturers variance, not most mods.
Op, the problem is in Proper Coil grounding and/or proper 510 grounding. Any loss = higher resistance readings.
Recheck coil tension - loosen and re-tighten.
Clean the 510 connections on Mod and Tank with q-tip and alcohol.
Fire the Mod with no tank attached.
Install tank and screw almost flush, but not quite.
Fire mod and select New coil again and read ohms. Note if any changes and if better or worse.
* sometimes the Coil may not make clean contact with the base of the tank*