Thanks guys. I do think thickness and bottom profile has a lot to do with it. My 100L swift is 6'3x20x5.4 (190x51x14 cm) so it's deep in the water and just rolls.
Just looked at smik, their 6'0x22@106L doesn't provide thickness and tried searching but couldn't find anything.
@hilly and
@robbo1111 do you know their thickness?
@Pasquales the sunova 95L is 5 3/8" (and rest of dimensions are similar to swift) but the bottom profile is more flat.Maybe it's the rider that is a problem?