Diana P-Five shooting high: my fix

Hi all, I had a Diana p-five always shooting way high, too much to be solved adjusting elevation of the sights or using a dot.

I blamed myself doing something wrong, but then I tried adding 5mm to the front sight...
And immediately my issues seemed almost fully gone, I repeatedly hit a empty pellet tin at 10m freehanded.

It just seems a different pistol :unsure: