Menu items not showing in single post page mobile view

My site’s menu bar is working well at home page in both desktop view and mobile view. But when I try to see all the menus from a post page on mobile view in incognito mode, it’s not showing.

I need help to be honest. It’s been 4 days, and I’m working on just fixing my my header again and again.
I’m learning from my mistakes.

Whenever I need help, I post here. But it takes too much time to get a reply from tagdiv team that’s why I reset my site with wp reset plugin and started working with it from the beginning.

This is what I’ve been doing in circle : Trying > Making Mistakes > Fixing > If it doesn’t get fixed, I try to reach tagdiv team here, but it does not work all the time, even after getting indications > Then I reset my site to start working on it from the beginning 😅

I’m sharing two images.. Check them out please. and tell me how to fix this problem.