Lumpy CFI wrote on Nov 19^th, 2023 at 10:34pm:

This is an unflyable product: requesting support. I can't start a new topic, so I'm replying to this related issue. I bought 777F through MSFS Marketplace.  When taking off I encountered an issue that the engines were not responsive to the commanded throttle position after takeoff.  The result was an aircraft stuck in Thrust REF (TOGA power setting) even though the animation clearly showed the throttles moving as expected with my flight controls).  N1 was stuck at max power setting.  I troubleshot all assistance settings, turning all related assistance off.  Same result every time. I uninstalled the version from Marketplace and bought the version directly from the CS website for another $20.  Same result.  After some time period the N1 thrust gets stuck at whatever power setting is selected regardless of the in-sim throttle position. Please help.

I think you have a similar problem to the OP.  If the autothrottle is on you cannot override it manually (unrealistic I know).  When you take off in TOGA using VNAV, the autothrottle expects you to climb to the altitude set in the autopilot even if the AP isn't on.  So it maintains TOGA and the CLIMB thrust. So if you stop climbing too soon, you will quickly overspeed.  Again, to stop this behavior you need to turn off the autothrottle arm switch.  I never noticed what the animation of the throttle levers does.