Time fields auto populate

I have a custom post with several pods fields, multiple items are ‘time’ fields with empty values permitted. On saving each post every time field, up to 10 of them, auto populate to ‘now’ except the fields I have inputted a time for, so I have up to 10 fields which I have to then delete the value and update the post to get rid of them. How do I switch off the auto populating time?

Cheers