Planar Reflection disappear

Hi! I have a problem with Planar Reflection. Whenever I move away or turn the point of view, planar reflection disappears. How can I solve this problem?

4 total PlanarReflections (PR) in scene: 2 pools, to bathroom wall mirrors.
All settings on PR’s are exactly the same.
Two PR’s work excellently,
the other two do not.
The two that are great are:
the larger pool,
and one of the bathroom wall mirrors.
The two bathroom wall mirrors are
the exact same size,
one being rotated 180-wz,
and translated 7-lz.
The pools are
the same orientation-lz(wz),
but at different “heights” by 3-lz(wz).
Wether in editor-mode, or game-mode, the two problem PR’s will work if the camera
is in just the right spot,
at just the right viewing angle.
If I build the Reflections, the same PR’s still malfunction, but for different camera
and angles.
I am on 4.22, with a GTX 1080 (i7-5960x, 32GB, m.2 1TB).
Thoughts ?