For some reason 'edge aware' editing has been removed for 360° equirectangular DNG images which creates a seem when editing. However if you open a JPG from the same camera and use the Camera Raw filter it does use 'edge aware' but obviously you have lost all the extra colour data.
Support says it is becasue it is not recognised as a 'REAL' 360° image because the camera is 'not on the supported list', but this was never a problem for the past 5+ years. The JPGs are recognised as 'real' but DNG's are not from the same camera. If this is down to meta data conflicts then a simple 'edge-aware' button would be an easy solution to tell it that it is an 'real' 360° equirectangular file.
It seems Adobe is against 360 photograpy as it removed the 3D editing feature not so long ago?