Use of the sickle throw will suddenly devolve into a constant swing action and it is difficult to stop it. Controls have limited response. Quick slot switching does not respond. Re-engaging magic sometimes interrupts if stamina allows. Today ax pick just remined unresponsive and I could not swing or change tool in any way. Other keyboard input works but nothing dealing with the weapon/tool.
This happened once to me - again, sickle throws in rapid succession seemed to be the initial trigger. Hitting "R" to cast a spell interrupted the melee swings and allowed me to switch items again, but the rapid swing came back the next time I threw the sickle until I interrupted with "R" and switched to other tools/enchantments for a short period before I tried the sickle again. After that, i avoided quick-spamming the sickle throw and it hasn't recurred.