737 engine rollback mid cruise

[AeroSpark]

Hello, I have a question for any 737 pilots if I may. Just returned from a week in Samos (stunning approach, but thats for another thread). About two thirds of the way into the flight the engined suddenly rolled back like they would at top of descent, for 10 seconds or so before coming back up to 'normal'. Pretty sure we didn't descend, I certainly didn't feel any change, so what could have caused it? A sudden change in wind direction perhaps?

[Gargleblaster]

Don't fly said aircraft, but could be due to a number of reasons: Instructed by ATC to descend and / or slow down for separation, descending to avoid bad weather ahead and aloft, slowing down due to reported turbulence ahead...

[redsnail]

I don't fly the B737 either, it's possible an ISA temp change caused an increase in speed and so to avoid an overspeed situation, the pilots decreased thrust (or the autothrottle did).

[BraceBrace]

At higher cruise speeds, the NG is simply very prone to overspeeding.

[AeroSpark]

Thank you