Poor nutrition, bad genetics, improper cure/dry, I’m sure there are several other possible reasons.

Sounds like you have a Pheno of the Pretendica that is famous for its cardboard terpenes and beautiful flowers?

Is it a purple punch?

An under fed plant often actually has more taste and smell believe it or not, just terrible yield lol. Is this an auto? Then I’d say you really can’t be very sure of genetics. What’s your temps like after about week 5 of flower?

I have seen this. I grew blue cheese organically in a green house that smelled so gassy I wouldn’t even light one up near her. It was a cut from my neighbors plant that when they finished theirs it looked amazing and frosty but had zero smell and taste. I believe yes genetics make a difference but not everytime. Nutrition matters and find my organic grows have more terps than my synthetic but less size, frost and harvest. I think knowing how to stress your plant a little encourages terpene production. Definitely harvest and curing techniques can ruin a terpy plant. Remember some terpenes start to evaporate above 80 degrees so if your temps are high you can loose terps.