Wet spots are common in clear glass container candles. They are caused by wax pulling away from the inside of the glass ever so slightly, resulting in a less than perfect finish.
Not all waxes will deliver glass adhesion, or at least not consistently. This is especially true of paraffin waxes.
There are a number of natural waxes that are best suited to clear glass as follows:
All three of the above waxes can provide perfect glass adhesion that lasts.
For paraffin or blended waxes, CS2 can deliver good glass adhesion and even when it doesn't, it still looks attractive in clear glass.
Paraffin waxes, such as SOASOLWAX 6213 and Kerax KW4140 do not adhere to glass fully, so the best you can hope for is to get an attractive finish without adhesion. Pre-heating the jars will help with this.