Not able to locate CORE in Automation->Add SmartApp->MyApps

Ive installed IDE and have created an app through IDE. Ive published the app and enabled OAuth.
On SmartThings, i see +My Apps tab under Automation->Add a SmartApp and Marketplace->SmartApps
I see all my apps that i had published over the IDE in the My Apps section. However, i do not see CoRE tab which would let me add/create pistons. Can anyone please help me out. WHat am I doing incorrectly?

Ive created the app over IDE via site
Ive got an Android Nexus 5x phone.

After the install in the IDE and publishing are you saying CoRE is not showing up in the marketplace - my apps section?

Or you did find it in there but now can’t create any pistons?

If it’s the first problem then I would recommend deleting and starting over. Making sure to follow all instructions to the letter.

If it’s the second then click on automations - smartapps and CoRE will be in there.