Make dev does not render welcomepageadditionalcontent

Hi All,
I have created development environment for jitsi-meet and I am able to run it by using provided command on developer guide, however when I add something to welcomepageadditionalcontent template under static folder, it does not render the additions, I am unable to see changes that I made on the template, however when I make it by using make command and upload to server then it starts to show changes.

Could you help me to understand what is going on ?