Joanne, just checking that you read what we said about changing Milo over to JWB gradually, not all at one? I wasn't sure, from what you said.
It should be over a minimum of 4 days, but preferably over a week or 10 days.
For example, over 4 days:
First day: all 3 meals should be one quarter JWB, three quarters Beta
Second day: as above
Third day: all 3 meals should be one half JWB, one half Beta
Fourth day: all 3 meals should be three quarters JWB, one quarter Beta
Fifth day: all 3 meals 100% JWB