There many problems with internal anchor in blogger. https://productforums.google.com/forum/#!topic/blogger/5MU_HH5T7rA
DON'T TOGGLE TO COMPOSE MODE and never SAVE/UPDATE in the Compose mode.
The blogger's toggle mode to Compose inserts
"http://xxxx.html" before # in /< a href="#_Bookmark_1" />
Replace "#_Bookmark_B" by
or for your page "/p/"
With this method you can toggle between
the two modes of blogger without problem.
but it will re-loads your page.
Create anchor links or bookmark links for fast navigation