Hi there! It sounds like you're having trouble using the SUBTOTAL function to count the number of visible rows after applying an autofilter. Here are a few things you can check to troubleshoot the issue:

1. Make sure that the autofilter is actually applied to the range you're trying to count. You can tell if the autofilter is applied by looking for the filter dropdown arrows in the column headers.
2. Check that there are actually visible rows after applying the autofilter. If there are no visible rows, then the SUBTOTAL function will return 0.
3. Double-check that you're using the correct function number for the SUBTOTAL function. The function number 2 is used to count numbers, so it should work for counting rows. However, if you're trying to count non-numeric values, you may need to use a different function number.
4. Try using the COUNTA function instead of SUBTOTAL. COUNTA counts all non-blank cells in a range, regardless of whether they're hidden by an autofilter or not. Here's an example formula you could use: =COUNTA(A5:A200)