I'm combining two filters using the Project = XXX and filter = yyyy Or filter = ZZZZ. The first filter does not have a date constraint, but the second filter has a date constraint where it's only looking at issues created in the last 30 days.
When I run the filters separately it should result in a count of 45 issues, but when I run then together it (see above) it results in 31 records. Could the date constraint be limiting the results?