Help prepping subfloor for laminate or LVT

I have a concrete slab in a garage conversion which is now an office. I’d like to prep it for laminate or LVT, I’m not sure yet. There’s some moisture in the concrete so I believe I’ll need a liquid DPM. On top of that a primer, and then self levelling concrete. Can anybody recommend a primer? I’ve been told Mapei self leveler is best, but I don’t know what primer to use on the DPM before the leveler? Somebody recommended Mapei Primer G but on their website it says “The surfaces to be treated must be clean and porous” which of course a DPM wouldn’t be. Any recommendations for a liquid DPM and a primer that can be used with Mapei self leveller would be great thanks! Does the above sound right? I’ve never done this before so any advice appreciated. As a bit of background for anyone interested, I had a builder in last year. They relaid the concrete slab in the garage because the other one had cracked in the middle. A couple of weeks later he put Mapei self leveler straight onto the concrete but within months it had lifted and it actually snapped my laminate. He didn’t use primer or anything. I have now removed all the self leveller and I’m back to the concrete base. The concrete has about 25% moisture according to my metre.