That happened with account wide achievements. Phasing doesn't work properly anymore because every form of phasing connected to player-specific quest progress and achievements is turned off now and just reads the progress of the entire account. So the two banners overlapping portray the progress of different characters in this zone. One triggered the green Anequina banner by completing the zone's story and the red banner by Euraxia Tharn is sourced from all your characters who never finished the zone's story.

Yes, they know it's an issue.
Yes, it's been an issue for years now.
Yes, after making achievements accountwide to save space they kept on releasing waves of new achievements connected to plain and simple stuff like "Visiting every guild vendor in the base game" and never exxplained how that makes sense in terms of saving space.

No, they are not planning on fixing it.
Enjoy your adventures in Elsweyr, fellow victim!