United is adding ~$1,200 to every flight change on my reservation

I’m hoping someone here understands United ticketing because I’ve spent hours on the phone with multiple United agents, gotten different answers from basically everyone, and no one has been able to explain this beyond “pricing is dynamic.” I’m also Premier Gold, so I’ve dealt with United changes quite a bit, and obviously a $1,000+ discrepancy is significant.

My sister and I had the same international tickets and were both looking at changing our return from Dublin to Italy. I monitored the fares for over a week. She consistently saw normal differences of roughly $50–300, while my reservation showed essentially the same flights at about around 1,200 more give or take.

I then checked flights out of Dublin as a control. I’ve changed this return from Dublin many times, and moving to the same/similarly priced flight has consistently shown $0. Suddenly, those exact types of Dublin changes were also showing me around $1,200 ish

The weirdest part: while one United agent was working on my reservation, something briefly corrected itself. I immediately cross-checked several flights and airports. My Italy prices suddenly matched my sister’s, and the Dublin change went back to $0.

Then it reverted, and the extra ~$1,200 flight change numbers came back everywhere.

Different agents have given me completely different explanations, and nobody has been able to tell me what actually changed during the brief period when everything priced normally.

I ultimately gave up and cancelled my ticket and rebooked, but I’m still really curious what was happening. Does this sound like a ticket/reissue/fare-construction problem rather than normal dynamic pricing?

I then had to pay way more to rebook my ticket