Just looks like a badly taped drywall seam.
Going to have to cut out the old tape, I'd add some more screws, sand down the area, clean off the drywall sanding dust and retape.
Most often someone pressed to hard when taping and pushed all the drywall compound out from behind the tape or used the wrong compound.
Most common issues first time DIY's have is using to narrow a drywall knife, (should be using an 8" wide knife) using to much compound and trying to make it perfect on the first pass which is never going to happen.
Apply a thin layer of mud, set the tape in place, and make a few light passes to set the tape in place and let dry.
Once dry do not sand it, just knock off and high places with the drywall knife, wipe off the dust and apply a second thin coat.
The last coat will need to be sanded first with a sanding sponge using a cirular motion, clean off the dust and apply the third coat.
The whole idea is to fill the low spots not build it up and make a hump.
Run your hand over it, anything you can feel will not be fixed with primer and paint.
That area will need to be primed, then painted.
Never use primer and paint in one for this one!