When the fluid bakes, it stays contained in an extrusion in the mesh as shown in the pictures. When debugging the obstacle, I found that it closed off a part of the mesh and the fluid stayed contained throughout the entire simulation.
ok, you made a lot of beginner mistakes in your scene.
First, "normally" you should apply scale and rotation, if you are starting simulations (at least with rigid body + cloth -> they wouldn't work if you had negative scales as you have here in your file).
Second, your normals were wrong on your plane.001. And just hitting "inverse" doesn't help if they are wrong. But...you can "repair" them by adding a solidify modifier to your plane.001 (i used thickness of 0.03). By this you get "automatically" blue faces and the simulation works then properly, if you "uncheck" the inverse for the flip-fluid obstacle settings.