Sounds like you have an unrelated issue compared to the rest of us then. Getting a numb dick is a possible side effect of excessive alcohol intake. If you only get this issue when you drink, it sounds like you aren’t suffering from the same Finasteride-induced numbness issue as others here.
As mentioned previously, Finasteride-induced genital numbness does not fluctuate, it is constant and significantly reduces sensation of foreskin and scrotal tissue, to the point of being unable to feel pain or pleasurable nerve response from touch. Drinking makes no difference, abstaining from alcohol makes no difference, it is permanent 24/7, 365 days a year.