Updated to Classic 10.2 with Big Sur and discoffered Merge Panorama longer works for multiple rows (spherical panorama's) If I try to merge three columns and three rows I just end up with the top row. It doesn't work with HDR Panorama either. Frustrating, I now have to export to TIF and merge in the remarkable PTGui.
Be sure to include the first ten lines of the menu command Help > System Info. Provide all the details, rather than linking back to this thread -- experience shows that Adobe developers tend not to follow the links. Product developers read everything posted there, but rarely participate here, which is primarily a user-to-user forum.
Also, upload a sample set of photos to Dropbox or similar and include the sharing link.