Feels like something else is going awry.
I'm going to need kernel & system logs to be able to tell what might be happening.
e.g., over SSH via Wi-Fi, run
klogd, then do stuff for a while (you mentioned cbz, so, try paging a few times in one). Then start an USBMS session and let it fail, and *now* run
logread and send me its output
.