Problems Statement:
I had been able to create new modules by creating 'Menu' element, creating extension of 'MainMenu' menu and then referencing my custom menu there. I had deployed a new development VM with Product version Finance and Operations (10.0.5) and platform version 29, which was latest available till date (1st January 2020). I developed a new Menu the same way I used to do but it's not showing in Modules panel in left side. I built all the models and run db sync, still the problem exist.
Solution:
On my visual studio I set a display menuitem from that module as a startup project and ran with F5. It forced the module to show up.
References:
I asked this question on community when I faced the issue first.
https://community.dynamics.com/365/financeandoperations/f/dynamics-365-for-finance-and-operations-forum/376309/d365fo-new-custom-module-not-showing-in-update-29/998061#998061
