Invoice Total Amount Tolerance

Hi

We are on 12.1.3

We have set our overall tolerance limit to $50 for the Invoice. We have no tolerance active for Line qty & price but only Total Max Amount se t at $50.

We use 3 way match.

I have a PO with 3 lines, Invoice comes in, we match it to PO and each line is off a little bit, example below

Line 1 is off my $24

Line 2 is off by $20

Line 3 is off by $16

Overall Invoice is off my $60.00.

The invoice does not get on hold. Are we doing something wrong? We want any invoice which is over $50 off (does not have to be a particular line off by $50)  but Cumulative they are off more than $50.