Hi DEV7591, looks like I could reproduce your issue with missing underwater post processing material. Is this the effect you mean, just having ripples but no real underwater shading when looking upwards from within a lake?
while it should be this one?
I just came across this effect while playing with Channel depth parameter. Good one using 500 as value, bad one when increasing to 2000. Just found that while experimenting… Maybe this is your issue as well?