Dexter, I did not upgrade, still on 4.4.
I'm not sure what introduced this issue, I have it since ~3 months. I ruled out PTA and Envtex. Unchecking Bathymetrie in Options also does not help. It's with P3D default ships, Nielsens AI ships, TFX and RTMM ships and float planes (in fact all wakes show the issue).
For the test with the container ship I explicitely changed that sim. cfg of that ship, to no avail.
Karl