Can fairy liquid residue cause no bond between thinset/floor

[D215YQ]

By way of an update I could not find the recommended stuff out here for love nor money. The only primer I found that mentioned vinyl here was 14€/sq m, or twice the price of the tiles I'm laying :( ...so instead I bought some more expensive tile adhesive from Weber (a good quality known brand here) that specialisies in tiles over tiles and has special resins to aid bonding to non absorbant surfaces. On my test patches, it is sticking better than the cheaper cement which is still sticking quite well (the strength of the bond seems to have increased a lot from when it was 24h cured to 1 week cured, so maybe it takes a little longer than I though to form a good bond).

Had no problems with the old tiles nor new tiles, and I still haven't grauted the new tiles so I am sure it's not just the graut holding them in place.

So looks like perhapos it was just the fairy liquid or something else on the part of the floor where the tiles failed and now I am just using lots of warm water to prep the floor with no detergents whatsoever.