We have an Icom M34 and it does the same thing - not all the time and not on every channel, but primarily on Ch 16 when it happens. Seems to be worse near a major center than away from. It's annoying, to be sure.
1984 Fast/Nicholson 345 "FastForward"
".. there is much you could do at sea with common sense.. and very little you could do without it.."
Capt G E Ericson (from "The Cruel Sea" by Nicholas Monsarrat)