Not every module has resources, but does have a tab for the resources.
Check the module below that should show you some resources:
https://gettingstarted.mendixcloud.com/link/module/82/lecture/529
I am having a similar problem. Regardless of which learning step i am looking at, the resources tab remains empty.
This one for example: https://gettingstarted.mendixcloud.com/link/module/312/lecture/2359
and this one: https://gettingstarted.mendixcloud.com/link/module/312/lecture/2360