It is likely caused by seasonal movement. Is this a ranch house with truss a truss roof directly above the kitchen? It could be caused by "truss uplift" which is caused by the 2x4 bottom cord of your truss expanding and contracting with the difference in heat/cool between the conditioned living space below and and unconditioned attic above. Or it could just be a sloppy drywall job. Cut out the bad paper tape, and loose compound, use some mesh or self-adhesive tape and re-mud the corners. I like this tape, makes it very easy to do both inside and outside corners for the non-professional. I can tape an inside corner with one coat using this tape, and get a nice straight corner. Much easier than just using regular paper tape. To me the added cost is worth the reduced labor and rework.
https://www.lowes.com/pd/BEADEX-Brand-100-ft-Corner-Bead/50012438
More details on truss uplift here:
Truss Uplift | Carson Dunlop Home Inspection.