I've had that happen several times and I found that a "RESET" of the IC-7300 cleared up the problem.

If you do a full factory reset, make sure you save all your settings on on an SD card before you start
or you will have to enter them all back in manually.

I eventually found that my problem was caused by a bad factory barrel crimp on the power cord where
the flag fuse was spliced to the power cord.  I re-crimped the connection and have not had another issue.
Up until I corrected that problem, I had thought I had an RFI issue and had snap on ferrites on everything.