Fender Acoustic 100

[Anand00028]

This amp ( Fender Acoustic 100 ) comes with a " Whizzer " cone.
Not sure if it's just my amp but it tends to break up (flutter ?) at high frequencies, especially my voice.
I reached out to Fender and they sent me to a local authorized tech to check it out. He felt it was ok. I really don't think I'm imagining it since I have a lot of other gear to compare to.
I'm taking it to another tech on my own. He said it could be a crossover issue.
Would appreciate feedback from others who have the same amp or amps with whizzer cones .

Thanks in advance.