Radio problems

My first post on this forum
I didn't think it I would have a problem this soon after purchasing my 2009 prius (only 4,000 miles) Package #2

For some unknown reason, my radio has, on 4 occasions, lost control of its volume setting. It jumps around going as high as 30 and as low as 1 as if I was turning the volume dial back and forth non stop. Turning the radio off then on doesn't fix it. I turned off my cell phone to see if was interfering. Turned the steering wheel slowly left and right (thought it could be a wiring problem inside) didn’t do anything. Turned the A/C and fan on and off did nothing. Trying to adjust the volume only delays it jumping till I stop.

Dealer wants to see the car while the problem is occurring.

Any thoughts

Thanks

 

I found a previous post by Prius77094 with the same problem

sorry about starting another post

 

thanks for the reply alanh
I'll try some of the technics use in that post