Posting date and time mandatory in production order

after clicking start button and putting qty to manufacture, it is showing that Posting order date and time is mandatory. But in production order, these fields are not there and checked form also
Kindly help

Installed Apps

ERPNext: v8.0.10 (master)

Frappe Framework: v8.0.13 (master)

do you have any customizations ?

no customisation