Another Stupid Leveling Question.

New to class C but had several TTs. I bought the Camco 3 step ramps to level our RV but several times, when I go to use them, especially on the front wheels, the RV tends to just shove them rather than go up on the ramps. It works fine in the rear. I tried shoving them against the tire as hard as I could but they generally slide along the pavement. Sometimes only one will slide while the other stays put which really messes up the leveling process. I suspect I would have the same issue with leveling blocks. I never had this issue with the ramps I used on my TTs although they were just a continuous ramp and not 3 stepped like these are. Any suggestions?