Yeh, that’s how the scientific method works.
Observations don’t support a model, or a model doesn’t support observations.
Think of a reason why.
Test that hypothesis.
Repeat until you think it’s correct. Hopefully other people agree with you.
People are also working on modifying General Relativity and Newtonian Dynamics to try and fix the model, while other people are working on observing dark matter directly (instead of it’s effects) to further prove the existing models. youtu.be/3o8kaCUm2V8
We are in the “testing hypothesis” stage. And have been for 50ish years