Missing data in formula with envelope curve

Hello all,
with two formulas i calculate the upper and lower envelopes.
Both envelopes have X-axis from 0-60 sec, but different number of values ??(372 and 349 points).
In a other formula I subtract (UpperEnvelope – Lower Envelope)
Surprisingly, this result has only a length of 0-55sec and 349 points.

Why do I lose this data, respectively 5sec of time?
How can I force the calculation to consider all points?

Thank you for your feedback