I just lifted this from the Ritani website. Yours should be right.
We don’t recommend going any smaller than 1.5mm in width. While thinner bands can look beautiful, they will wear down and can even crack over time. Thinner bands are also more susceptible to bending and losing their circular shape. For extra security, choose a stronger metal like platinum for an engagement ring with a thinner band. If you’re rough with your jewelry or work with your hands, a band of at least 2mm will be a more durable option for you."
Hopefully it is just a delay!
Checked again this morning. Scheduled for end of the day today. (Whew)