Tolerance was my only issue for the longest time too. But in the last few years I started to get mild insomnia in the beginning of the night if I had coffee lat

Tolerance was my only issue for the longest time too. But in the last few years I started to get mild insomnia in the beginning of the night if I had coffee late in the day. It wasn’t making me feel active or awake but just unable to fall asleep even if I was tired. So I’d spend about 2-3 hours unable to fall asleep while tired. Now my cutoff is actually 11:00 and I try not to have any after that