Dolphin Star won't climb walls

by Francis
(Grenoble - France)

My pool is a perfect rectangle 25ft X 12ft, shallow end is 4ft deep and deep end is 7ft. It is fully covered with small glass tiles.

I got a brand new Dolphin Star with the adapted foam rollers.

Irrelevant of the selected program (short or long), it sweeps the floor well but when it hits the wall it starts climbing and get to an approximate 45 degree angle, the back end roller and caterpillars do not touch the floor and then it goes back down. It tries several times to climb before going backwards.
Interesting enough when I put it in water (after draining carefully trapped air and wetting the foam rollers), the first time it hits the wall it climbs correctly but then it never does it again as if by climbing once it has picked-up additional water and it weights too much to climb.

The diameter of the foam rollers is larger than the one of the caterpillars front wheels, only the rollers touch the wall and the caterpillars do not.

I tried to modify the turn radius by playing on the 2 handle floats with no difference in behaviour.

Any insight on what to do to make it work as it is supposed to do?

Thanks in anticipation!

Desperate Frenchman