Is the top of the toilet flange even (or close to even) with the finished floor? If it is too low – then use two wax rings. One regular wax ring on the bottom and one (or more) with the plastic horn insert on top. I have seen leaks like you describe if the glued flange is not really glued in all the way. Take a look at that – if your floor and flange is flush. Sometimes you need to shim the toilet if the floor is uneven or the flange is to high.
Don’t use 2 wax flanges, the excess wax can crush and fall into the pipe resulting in poor drainage or clogs. Use a proper flange build up kits from 1/4″ to 1″ THEN use a can’t leak wax seal with plastic no leak insert.