Missing one of the Primary Menu sections in breadcrumb

Issue Summary

HI all,

My Primary menu structure are like this:

--Section 1
---Section 1.1
---Section 1.2
---Section 1.3
--Section 2
---Section 2.1
---Section 2.2
--Section 3
---Section 3.1
---Section 3.2
---Section 3.3
---Section 3.4
---Section 3.5
---Section 3.6
---Section 3.7
---Section 3.8
---Section 3.9
---Section 3.10
---Section 3.11
---Section 3.12
--Section 4
---Section 4.1
---Section 4.2
---Section 4.3

The structure is shown as above. However, The breadcrumb cannot show the longest section at all.(i.e. when i click "section 3.1", it cannot show "section3" on the breadcrumb).

Anyone has the same issue as well? Thanks.