This appears to be a long outstanding issue:
and has been added to the "TODO" list at:
The problem appears to occur when you have a relatively small fluid object compared
to the domain size.
Generally speaking, using an UVSphere as an inflow object isn't a good idea due to the
smaller triangular faces at its "North and South poles".
A less problematic option would be to either use a cube or a level 1 or 2 subsurfed
cube (apply the modifier), if you want to keep the inflow object the same size.
Also, it's good practice to keep all of the fluid simulation elements at a scale of 1
(Your inflow object had a scale of .025, Apply Scale, Ctrl + a > Scale).
(Dimension of 0.05).
Here's your blend file modified using a Subsurfed level 2 cube (subsurf modifier applied)
at the same dimensions (0.05) as the UVSphere inflow object:
Using an inflow or obstacle object that contains faces with even/equal surface area
doesn't guarantee a successfull fluid simulation result when the voxel size approaches
the size of your fluid object(s). In this case, the only option would be to scale
everything up; which can necessitate tweaking any animation you may have on your fluid