In my scene the liquid goes through the plane or grid, no matter what the settings are, but with a cube it works as it supposed to.

I've tried with option "is planar" checked and with surface thickness other than 0 but the effect is still the same.

I do not know how to add blend files here so here is a link to OneDrive with my file:

https://1drv.ms/u/s!AlGcA8SSj2fdgcUujK3RFLDcKzsZ-Q