I wonder if its a security issue with first time transfers. Tried a Cap One transfer a few days ago (to take advantage of the bonus) and now In the same boat as
UA Fan - CapOne says they've sent the miles but theyre not showing up in my Avianca account. I've transferred from other programs - Amex and Brex - with no problem. Crossing my fingers that mine will resolve itself within the next couple of weeks too!