I agree with Ferrent that this is normal. These bowls seam to work best with my ferts https://www.amazon.com/dp/B00243W67G/ref=cm_sw_r_cp_apa_glt_fabc_PPGPYV90R8J5CMES94D9
Not unusual behavior, he may like some tossing toys. For water bowls you have to go heavy so they don't do that. Try something like this. We used to use those and they are fairly heavy and hard for them to grab.
This is the thickness I'm suggesting, but the earlier bigger one weighs one third as much as my cat...https://www.amazon.com/dp/B00243W67G/ref=cm_sw_r_cp_apa_glt_fabc_N6V4RVNN91P098YD6GF6