One thing to keep in mind is what model you are looking at.

There are multiple versions of FICO/Vantage that are all based on different parameters, and they vary significantly. The scores between the 3 different bureaus can be different from one another as well. Make sure you are comparing apples to apples here.

You need to pull your actual credit report (not just an opaque number on your banks dashboard) and review it and see if there’s something wrong on it that might explain this drop. If there is, you can dispute it with the bureaus.