How to prevent 2 Note styles from merging?

My documentation includes a "Note" box and a "Tip" box that both derive from
a "Note" style. That is, a "Note" has a horizontal line on the top and
bottom of the paragraph, as does a "Tip" (a "Note" is supplemental
information, whereas a "Tip" is an alternate way of doing the same task).

I have many places in my document where a "Tip" immediately follows a
"Note," and vice versa. The problem is that I have to separate the two
paragraphs with an additional hard return. If I attempt to delete the extra
space between the paragraphs, the two chunks of text are merged, with the top
horizontal line above the "Note", and the bottom horizontal line below the
"Tip."

I realize I could probably just duplicate the "Note" style, and call it a
"Tip" style, and then the two paragraphs would not automatically merge.
However, I was wondering if there was a way I could just turn off the
auto-merge feature.

Thank you for any suggestions.

Tim