changelog is confusing me

I'm looking at https://packages.debian.org/buster/isc-dhcp-client and I see
that there was a binary NMU - 4.5.3-3+b1 - but when I click on the "Debian
Changelog" link on the right-hand side under "Debian Resources", it takes
me to the changelog for 4.5.3-3, not 4.5.3-3+b1, which is what I was
expecting.

I'm not sure if this is expected behavior or not, but the people who can
fix it if it isn't aren't going to unless somebody tells them about it, so
here ya go.