It’s been frame 592 and the water not yet filling the bottom. Is there a way to add more water in short time without adding more frames? (but i’d like to keep time scale at 0.5, 1 looks so unnatural and too fast.)
Try to add an INFLOW Object in the flow Behavior, depending of the size of the object, will add more liquid to you scene.
It seems you are using an Geometry as Flow behavior, Change it to inflow.
And, if there´s many water, Use an Outflow or decrease the size of the inflow object.