Tags and Filters - some customers dont appear

[madmarketph]

I tag all my deliveries based on the date of customer delivery and then type the tag daily to get the complete list of customers for delivery that day.

today, after 3 mos of using shopify, the system missed out on 2 people who had the tag.

Does this happen to anyone else?

What can be done about it if it is a system error?

Is there a better way to get the dates?