This is a sign of some serious background physiologic issues…either congenital or diet/environment. 30y/o males don’t need TRT. So there is probably some very serious off-the-bike stuff going on. Normal 30y/o men don’t need TRT.
As others have said on this thread, double that. See how you feel. Over the next couple months, slowly work up to 90g/hr. See how you feel.
We’re learning so much a bout fueling with every passing week/month/year. 
I’d agree that 40g/hour isn’t nearly enough, and if you’re coming into those rides without your stores totally full, you’re not going to get nearly as much out of your body as you potentially could.
I’d shoot for at least 90g/hour and start to work your way up from there on harder/longer rides.
We’re learning that all of these endurance efforts are so dependent on carbs. For someone like you who often rides 12+ hours/week at your current weight, you should be looking at ~585g of carbohydrates each day. That’s 13 cups of brown rice for reference, and if you get back into the volume you were doing over the summer, that number will only increase.
If you’re not currently getting nearly that much in, I’d recommend starting to incrementally work your way up and take note of how you’re feeling along the way. Each of us is unique, and this graph is just one guideline, but I’d say it’s definitely worth a shot!
