Suspension issues, driving me mad

I have a 2011, TDV8, my rear passenger side suspension is creaking like a 1980s mattress, you can hear me coming about 400meters before i arrive,
i have replaced some of the usual suspects as part of routine maintenance, but i was under it yesterday while having 4 wheel alignment and it seems to be coming from the air bag/ strut, the strut was replaced last October. also the ride is a little hard at the rear (starting to get a squeak on the diver side rear) but not all the time. the rear airbags haven't been replaced in the 6 years I've owned her.
i am after some help on what it could be, its showing no codes, it goes up and down no problems, it creaks on the way down but not up. I have tried silicone spray on individual bushes to eliminate them without success.
any help would be appreciated. i am pulling out my hair

It could well be that the arms etc. have been torqued up whilst 'hanging' rather than at ride height as per workshop manual (I'd also check the top mount for the airbag and the damper, not easily accessible).

Initially I'd suggest relaxing the torque on all the fixings on both sides and jacking the suspension up so the wheel hub centre is ~480mm from the wheel arch with your tape measure vertical, re-torquing all the fixings, taking note of any ripped or cracked bushes, then road-testing again.