Yes. Assuming you already checked herb/med interactions for any potential issue, and you ruled out tolerance from prior substance use, then chances are there's a digestion issue. One time it took me 5 hours until the effects of a capsule hit. And many times it never did. (Think of all the people taking life-sustaining medications that are probably not even digesting them--but they take them every day so the blood levels build up over time anyway.)
I often find that nothing will happen until I eat some potato chips. Or something easy to digest which has some carbs and fat like those. When you fast for a while, your stomach goes into sleep mode basically. And when you put a capsule in there, it doesn't see it as food, so it doesn't wake up to digest it.
Also, it's important to be sitting upright for proper digestion, not standing, working, moving around, or lying down. In biology the phrase used is "rest and digest." But really it should be "sit and digest," since you can also rest laying down, but not digest properly that way (ever gone to bed with a full stomach and woken up in the morning still full?).
Furthermore, the capsules are made of tapioca starch, which can be a bit difficult to break down unless your stomach is well-acidified. Some people's stomachs don't produce enough acid, and some people even take acid-BLOCKERS so they can barely even digest food anymore (not knowing what is going wrong with their health). In this case you can put the capsule in a cup with a little vinegar. When it starts looking a bit puffy, add some water & sugar/honey and chug it. That basically pre-digests it for you.
One other thing is something that a number of people have reported, which is that if you don't taste the substance you are consuming, somehow your body is less likely to digest it and absorb it. What I do now is, I'll take a little taste (by piercing the capsule a bit with a knife first), then I'll swallow it. I find this really helps the body know to expect this is something to be digested.
It's really funny and interesting studying digestion. Even top scientists are still in disagreement over this topic. You won't find any field of science so completely divided as the field of nutrition, in which some experts say fat is bad for you, and some say it is good for you. Some say cholesterol is bad, some say it's good. And on, and on, and on.