I've seen a similar discussion to this one relating to the TomTom Rider 450 but I thought I would add some additional tech to the subject. I have just bought a Rider 550 and on the whole I am very impressed although not as fast as the adverts would have you believe. My main issue though is I have paired the device to my phone and to my Cardo SHO-1 headset. When I get directions through the headset it sounds like a darlek. For those that never watched Dr Who or have no idea what I am talking about, it sounds crackly like there is a form interference. I have seen the comments about repairing and I have to say, coming from a very techie background, that that's a cop out. That's like something we used to say years ago about rebooting your computer and whilst sometimes both of those have merits, I would say not in this case. I say that because the device is new and my iPhone 8 plus is also pretty new. My TT 400 was actually much clearer. Google maps from my phone to headset is crackle free so the issue has to lie with the TomTom.
I have to also point out that it's not just traffic that I get the crackle but directions and also the new read aloud SMS feature. The latter was so poor that it was an utter waste of time trying to hear.
Come on TomTom please surprise us with a valid response and not a repair suggestion which is total pants.