Thank you Jorgen for your reply. I did try your suggested procedure but that did not solve my issue.
However...... after doing some additional checking in the FS Control Settings I discovered that a Control Axis for the" FS Yoke" had a Control Axis assigned to the Throttle Axis. How that happened I do not know?? but when I canceled that assignment I no longer had the power fluctuations.
Cheers....Herman