A filter that returns plausible rows may still use the wrong inclusion rule. “East and open” is a narrower request than “East or open.” Test records that separate those meanings before applying the formula to a long work list.

In Microsoft 365 Excel, Excel 2024 or Excel 2021, prepare headings ID, Region and State in A1:C1. Put T1/East/Open, T2/East/Closed, T3/West/Open and T4/West/Closed in rows 2–5. These four invented records cover every combination of the two conditions.

Compare the included identities

FILTER uses a source range, matching Boolean inclusion array and optional no-match value. Multiplication implements AND; addition implements OR. Enter these formulas in separate empty output areas:

=FILTER(A2:C5,(B2:B5="East")*(C2:C5="Open"),"No matching tickets")
=FILTER(A2:C5,(B2:B5="East")+(C2:C5="Open"),"No matching tickets")

The first result should contain T1 only. The second should contain T1, T2 and T3. T4 belongs in neither result. Inspect the IDs, regions and states together rather than checking only that one result is longer.

T1 satisfies both conditions, but the OR result should still contain that source record once. The condition determines whether a row qualifies; it is not an instruction to make a second copy for each condition that the row satisfies.

Make the empty outcome intentional

For a separate no-match check, change the AND formula's region condition to North. Expect the specified No matching tickets message. Without the optional empty-result argument, a genuinely empty result can produce #CALC!. An error in the inclusion array is a different condition and can still return an error; the no-match message is not general error suppression.

Decide what the real report is meant to include and write that rule in ordinary language beside its output. Preserve the original source records while changing the formula. If the two conditions come from user inputs, record those current selections with any exported result.

Finish by choosing one qualifying record, one that meets only the first condition, one that meets only the second and one that meets neither. The accepted formula must handle all four according to the stated rule. This check is stronger than accepting a row count that could conceal the wrong members.

Sources: Microsoft: FILTER function.