Objects that reflect in the water have imperfections when the camera is closer and depending on the angle of the camera which varies the artefacts.
Here is several image which shows in 1 the close camera, in 2 a small retreat with a different angle and in 3 the camera sufficiently distance and the expected result.
I reproduced the same thing with a PG:
Water itself does not do this problem. It’s just the objects that reflect in the water.
The results on my project: (It’s really very ugly )