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.
".. 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)
1984 Fast/Nicholson 345 "FastForward"