This is probably part of an age old and oft raised issue.
The answer is usually that the metering in FCP is different from that on your Beta deck.
One test for you, is to output your Ref Tone & Program to tape, then batch both of them back in and see if there’s a difference between the Tone and Program.
If there isn’t, you can be assured it is a difference in metering between the two devices.
As i said, this issue has been covered often since the arrival of NLEs, but I can’t point you at any definitive discussion. Maybe someone else can help, there.