Is anyone experiencing stomach pain after taking Maff?

I've been taking Maff for about 6 to 7 months, but lately, my stomach hurts when I take it.
After taking it, I start feeling sharp, stabbing pains in my stomach. It's not so bad that I can't go about my daily life, but it's quite painful.
(When it's severe, I have to lie down for a while, so it does interfere with my routine.)
How should I put it... it's a hard-to-describe kind of pain..? It just feels like intense stabbing sensations.
This symptom started about 2 to 3 weeks ago. At first, I thought it might be because I love spicy food so much;
I often use Buldak sauce or Sriracha as a base when I'm following my usual diet.
I heard that the stomach or intestinal walls could be irritated because of that, so I quit spicy food and decided to temporarily stop taking my supplements as well.
While I was replacing my protein with other things like chicken breast and eggs instead of supplements,
I started taking Selex supplements from the convenience store last week. And that was fine.
Since I felt better, I wondered if everything was okay now, so I tried taking my regular supplement again today,
and although it wasn't as bad as before, my stomach still hurts a bit.
When I first briefly stopped my supplements, I switched from Maff to Selex for a bit and then stopped everything completely.
Back then, my stomach hurt even when I took Selex, but now taking Selex doesn't cause any problems...
I'm wondering if it's an issue with the Maff supplement itself (like improper storage or it just doesn't suit my stomach),
or if my gastrointestinal condition is simply poor right now, meaning I shouldn't be taking any supplements at all...