Two clocks, not one
When people ask how long they have to wait before a cash-out refinance, they usually mean one thing: how long they have owned the property. Under the agency rules that is only half of it. There is a clock on your ownership and a separate clock on the mortgage you are paying off, and either one can be the thing holding a refinance back.
These are the cash-out refinance seasoning requirements published by Fannie Mae in Selling Guide section B2-1.3-03. Freddie Mac publishes its own version, and the two do not match line for line, so which channel a loan goes through matters.