I am creating a new module (my_module).
I placed a logo called 'icon.png' in Custom_addons/ my_module/static/description.
it is not showing in the Kanban view of the App I developed. I am able to see it when I go into my_module "More Info".
I am working in Odoo14 local server Enterprise
When I changed from developer mode to user mode the icon appeared. I am not too sure if this is the reason or the solution but it works for me.