Hi Ryan,
Thank you for posting your question in this community. From your description, when you open an Excel workbook with Filters in Microsoft Teams, you found that the filters are disappeared from the wordbook. And this issue is happened to all your workbooks with filters in Teams.
I also tried to reproduce this issue from my side where I created a workbook and applied filters to my data set by selecting my data set > Data menu > Filter. Then I shared this workbook with other users in Microsoft Teams and open and edit it in Teams. It seems that the filters are remained in the workbooks.
If there are any differences of my reproduce steps from yours, please point them out.
In addition, may i confirm the following information to further narrow down this issue at your convenience?
1: Does this issue happen to the other users when they open the workbooks with filters from Teams in your organization?
2: Try to open the workbook with filters from Excel browser and Desktop application and see the results.
3: Does the same issue occur to your local Excel workbooks or the workbooks in SharePoint document documents library? From this, we can ensure whether this issue is only happened when you open Excel workbooks with filters in Teams
Best regards,
Dihao