Disappeared from seatmap SFO-HKG; Cause for concern?

Greetings all,

I checked in for RNO-SFO-HKG just now for travel on 5/14 and printed boarding passes. The boarding passes look fine, including upper deck on #869 SFO-HKG, reseved via a W fare and GPU about 6 months ago.

However, when I look at the website, my seat assignment on #869 SFO-HKG shows "---" A check of the seatmap shows my original upper deck seat occupied, but I do not show up anywhere.

I called UA and the agent said that it is some sort of "glitch". She said that I am in the seat that the printed boarding pass shows on the manifest.

Given all the nonsense I've read here, let's say I'm a wee bit concerned.

How worried should I be?
Any suggestions for a course of action?

Thanks in advance