How to I solve an #OVERFLOW and blank formula?

I have a problem with some formulas that I am using, they are:

=MAX(COLLECT([Service End Date]:[Service End Date], [Account Number]:[Account Number], [Account Number]@row)) This one helps me find the most recent bill date for an specific account.

=IF([Most Recent Bill Date]@row = [Service End Date]@row, true, false) This one helps me know if the most recent bill date at row is matches the most recent bill date I have.

=IF([Most Recent Bill Date]@row < (TODAY() - 45), true, false) And this one notifies me if bills are needed.

The problem is that is working for some rows, but in other ones is just blank or it gives me the #OVERFLOW. How can I solve this issues?

Thank you,

Alfredo Arrieche