SharePoint column validation rules not showing up in PowerApps

Question

I have a SharePoint list that has custom column validation rules like LEN(CaseNumber)=10 to make sure a 10 digit value is entered. I then used PowerApps to build a custom form. Do the column validation rules NOT transfer to the PowerApps form? I can see the error message working if the column is required, but I cannot seem to get the form to recognize the custom user error message that I've entered in the list settings on SharePoint. I'm wondering if instead of putting the custom validation in the SharePoint list, I need to install it in the form code.