HY 270 anchor is rotating in a hollow after installation.

We have a hollow block density of 1450 Kg/M3, wherein we use HY 270 with mesh sleeve and HAS - U M10 after fixation and curing time we were able to rotate the anchor inside the hole without coming out and we did a pull-out test on the same anchor and the results shows the anchor can carry still the required load of 3.5KN.Now our material is rejected by the engineer, we need your advice on this matter and what are the possibilist to close this matter or what are the reason that make this anchor to rotate in place. Just want to address that the anchor is not over torque as per the same engineer.