I have a custom ID field on Contact table as the attached screenshot.
I used Power Automate to set ID to some of the existing contacts (circled in blue). As a test, I created a new contact in the red circle. The issue is that the new contact(s) do not respect the existing auto number values and cadence. Because I have manually set the IDs in blue through Power Automate in the same format, I expected the one in red to be "C00016" instead of "C00001." The ID is an auto number type field with the expression to set it such as "Cxxxxx" with the number increment by 1.

Anyone has ideas why the new contact does not follow the auto number format based on the existing records?