hmmm... that doesn't sound odd at all.
some do make while others don't.
but i think what you need to focus on is making sure the conditions are right.
Like the temperature, the water circulation, etc.
you can check this out for beta fish info.
it's not really really really in-depth but hopefully others in this forum could help you out too!
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-penelopedarcy
“Fish die belly upward, and rise to the surface. Its their way of falling.” Fish Tank Pet and Kefir grains