Mini-TOC question

I'm having a mini-TOC issue:

1. FrameMaker 2019 v15.0.4.751
2. Heading2 has auto-number defined as: a:Part < ><n+>. In this file, the part number is 2.
3. Footer is correctly picking up the part number using <$paranumonly[Heading2] and displays a 2.
4. X-refs are correctly picking up the part number using <$paranumonly[Heading2] and display a 2.
5. Mini-TOC is not. Instead <$paranumonly[Heading2] is picking up the Heading3MTOC & Heading4MTOC numbers.

MTOC Reference Page

MTOC on Body Page
The numbers in orange on the right should all be a 2, representing the part number for this file. Instead, they are displaying the numbes from the beginning of the MTOC line. What am I doing wrong?

Thanks in advance,

~Barb