I have an i7 64-bit system running Kubuntu 18.04 desktop. System boots/runs fine with 4.15.0-23-generic kernel, but with later -24 and -29 variants I get long pause in boot trying to connect optical mouse, and thereafter optical mouse connects/disconnects repeatedly and the boot doesn't complete. I've tried different optical mice - same problem. Can someone provide insight into what the problem might be and/or how to fix? Thx, Gus