If you tell a rule with no filters to limit to 10 DVDs it will stop them when they have 10 DVDs. Even if they are checking out a book.
If you tell a rule that is filtered to only apply to DVDs to limit to 10 DVDs then it will stop them when they have 10 DVDs and are trying to check out a DVD.
From the description you need to re-think how you are applying the limits and to what rules you are applying them to.
A rule that says "no more than 10 DVDs" should probably there. A second rule that says "no more than 5 Children's DVDs" would be applicable. If the fallthrough aspect doesn't pick up the 10 DVDs limit you need to apply it to the Children's DVDs rule *and* include Children's DVDs in the count on the 10 DVDs limit.
If you tell a rule with no filters to limit to 10 DVDs it will stop them when they have 10 DVDs. Even if they are checking out a book.
If you tell a rule that is filtered to only apply to DVDs to limit to 10 DVDs then it will stop them when they have 10 DVDs and are trying to check out a DVD.
From the description you need to re-think how you are applying the limits and to what rules you are applying them to.
A rule that says "no more than 10 DVDs" should probably there. A second rule that says "no more than 5 Children's DVDs" would be applicable. If the fallthrough aspect doesn't pick up the 10 DVDs limit you need to apply it to the Children's DVDs rule *and* include Children's DVDs in the count on the 10 DVDs limit.