Mathjax \label says "Label multiply defined"

What I’m trying to do

use the \label{equation11} to write math.

What is the issue

Using the \label causes issue where the label gets defined but as the live-preview updates, it gives the error “Label multiply defined”

Label ‘equation11’ multiply defined

I have to keep changing the equation11 to some other name everytime the live-preview updates.

\label{equation11} working:

\label{equation1} not working: