cam chain oil and filter effects

[CMF_Mike R]

since I changed the oil and filter the other week the cam chain has been a lot quieter on start up . Normally it has a good rattle but now its just a quick rumble .. I have changed the oil and filter in the past and its always rattled ...????
The filter did appear to have quite a good anti flow back valve on it , but so did the last filter .. which was the same brand "SolidAce"

Anyone else come across this ?

now I have said this it will rattle like hell in the morning