Couple of ways you can go.
First rather than limiting your data in the select statement you could conditionally suppress records on your status formula. This is the easiest but needs to account for any other summing you are doing any.
Second option. Adjust your AV+AL formula so it accounts for the NULLS. This way you will get sums even if it there is NULL. Then your Group condition selection will select either issue.
I am guessing it is something like:
Field a + field b.
Change it for the NUlls something like
if isnull(field a) then 0 else field a + field b
Do either of these fix the issue?