Cant put Banner on Shield

It won't let me put a banner on a shield I know this is a feature in Java but it should be in Bedrock  I really don't understand this  "Any parity issue that does not meet these criteria will not be tracked on the bug tracker and should instead be reported on" yeah I don't understand why this is not a problem  it's not in Bedrock it's probably a reason why it's not in the virgin I hope in the future it will be in Bedrock.