It may be helpful to use Chase's own vocabulary. Transfer means redeem UR points for airline miles or hotel points. You are not attempting to transfer. Combine means move points from one UR account to another. On personal cards there is no Authorized User requirement to combine, only that you reside in the same household.
This.
Iridium7777, be sure to use the term "combine" when talking to the reps.
For reference, link to Reserve UR agreement:
https://chaseonline.chase.com/resources/RPA0511_Web.pdf
See bottom of page 3.
The representatives are inventing an explanation because there is a technical failure which they do not understand and cannot fix.
Although this is generally true, the reps are correct if
Iridium7777 is using the term "transfer" rather then "combine".