With bits set in WGM22 WGM21 and WGM20 you are in the Fast PWM to OCR2A mode. OCR2A set the frequency of the Timer repeat. The reason you got output on pin 11 by changing the bit setting of of COM2A from 1 to 0 is that you set that output to toggle on compare match.
I think that you should be seeing 50% duty cycle at 125Khz.
When you use fast pwm to OCR2A you can not get variable duty cycle on pin 2A.
An excellent tutorial on Timers is by Nick Gammon
The Timer register summarys sheets at reply #18 are a good companion to the full AT328 data sheet.
Don't know why some of the helpers "help" with questions not with corrections.
I was tying to get you to do some research and think, and come up with the answer by yourself rather than just give it to you. I wanted to encourage learning. When you get into low level timer control with register settings, you need a good understanding of the details.
What did the data sheet tell you about the mode of operation of the timer with those settings?
The goal of this question was for you to discover "Fast PWM to OCR2A" and to understand that the pin 11 pwm output was not available because the normal OCR2A compare match duty cycle control setting was being used to set frequency.