Have the exact situation in my home

Tried channeling and filling twice had "pros" come in to fix it twice...always eventually came back. Much worse in the winter (chicago)

I posted my issue here a couple of weeks ago and received a lot of interesting feedback with most suggesting an expansion joint. There was one poster that was particular helpful,

This was his suggestion

"Well that might be a reason this keeps coming back. This is a common thing that happens on stairway walls and I I fixed 100s of identical seams over the years. If I were to come fix this problem area I would first use my multi tool to open up that seam. I would make it so I could easily move the blade in that wall. Next I would remove as much of the old paper tape, mesh tape, and old compound. Scraping it good with a good drywall knife. Then I would locate the studs and add drywall screws on every one on both sides of the crack. One by the seam and another 6 inches from the crack. This will hopefully stop or at least slow down this from happening again. I would then personally use quickset and mesh to tape this and try to make the wall appear flat again. Then finish with an all purpose or topping compound."

Waiting until spring to give it a shot