Crack along join between wall and ceiling

Hello,

This crack opened up several years ago. I've also had some minor subsidence on the same side but to the rear of this wall but the surveyor who came to look at that said it wasn't associated with that. The 'drop' is maximum 10mm at the stair end and probably a couple of mm at the other end. The movement has also affected some floorboards on the first floor above, which are a little uneven. You'll also notice the end of the RSJ that was installed when one of the previous owners knocked through the lounge and dining room.

The surveyor has suggested fixing the cracks with resin, but I was wondering if supporting the join with some planed studs and frame fixings or bolts (which can be caulked up and painted to disguise it) would make sense? I have a couple of adjustable props (can't remember what you call them) so could potentially gently encourage the ceiling back into place? Still recovering from the pandemic - let alone the cost-of-living crisis - so low-cost solutions are particularly of interest.

All feedback and suggestions very welcome.

Thanks

 

Thanks, so you think do nothing on the ground floor beyond filling and just take up the carpet and level out the floorboards on the first floor?