Calendar option visible in Project for the web App

Hi,

I have a managed solution in a production Power Apps environment that runs the Project for the web app. I noticed a "Calendar" option on the Project main form that was not there until last week. I then opened the unmanaged solution in the dev environment from where I export it as a managed solution, the Project table's form does not have this Calendar option. No other changes were made to the main form so where is this Calendar option appearing in my solution? 

I can confirm both solution versions are the same & no other user updated the solution.

Unmanaged solution Project main form:

The production app where the Calendar option is visible: