That weird about the stop in BKK... anyhow, it is not my agenda to fly HKG-BKK.
I called back CS today, and had a nice gentleman that did not modify automatically, but manually and was able to get me on EK385 from BKK instead of HKG for 113€ if I drop to SAVER, and 153€ in FLEX... so here we are !
The system can be weird, but some persons are more clever or less lazy than others. I'm glad I could do it.
Thanks to the new allocation as well as it seems we went from a packed ECO to some seats available.