Damp issue

I have moved to my current flat 2.5 years ago but only in January this year started stripping wallpaper/old carpets with a view to finally decorating.

There seemed to be a damp issue in the corner of the living room, next to bay window that has been treated by the landlord but multiple injecting chemicals from outside which never worked so finally they have sent damp specialist who knocked part of the wall off from inside, injected and re plastered- several weeks later still looks dry.

Then there was few floorboards that were in need of replacing at the back of the flat (bedroom) but on arrival contractors realised (after taking few floorboards off) that the issues was much more serious as the whole space under the floor was full of mud (!!), all joints were rotten and "pates" were pretty much invisible under mud/earth. On top of this, one wall had damp. Those were damp and timber specialists.

Fast forward few weeks - floor was dug out, plates/beams/floorboards replaced, wall covered with some kind of membrane (whole wall) and skimmed over. More floor had to be done in the hallway and second bedroom. 2 surveyors were here (landlord's one and the contractors' one) and I was told all will be good now. Also that part of the problem were air bricks that some clever spark blocked from inside by putting concrete over them. Those were reopened/dug out when the floor was being patched up.

Today I had another surveyor in to check condensation/mould issues and he had a different tool to check for damp, one that penetrates the wall somehow (previous surveyor had the "prong" one that now I was told does not penetrate to check inside the wall) - and going around the flat, his gadget was showing 100% (!!!)moisture pretty much all over the flat, including the freshly done wall with the "membrane" on it as well as the wall in the living room that was done several weeks ago. The 100% was showing to about a metre high on all external walls and also wall between my living room and the shared hallway (it is a ground floor conversion). Then higher up going down to high 80s.

At some point I thought it may be faulty so asked him to test partition walls - there was zero on those.

He said this is rising damp. Previous company told me all damp was sorted. 

I am a bit lost as who is right and what is going on really as the difference in "opinion" is a bit extreme.

This is an L&Q flat and they are not particularly keen on doing any proper works, patching things up is more their style.

Luckily I was able to work from home for most of the works up to date but having to be camping in the camped with all my stuff living room for weeks with limited access to bathroom (stuff in the bath as well) and no access to 2 bedrooms was very tiring and t find out at the end that (1) original problems wee not really sorted (2) there is more problems ... 

I am horrified at this "discovery", confused how 2 "specialists" can come up with such different opinions/findings and not sure what to do now.

Of course I will go back to the L&Q surveyor when he gets today's report but - can anyone share their own experience if they had to deal with similar issue? 

Many thanks...