So when printing through cura with a usb cord, if I have to restart a few prints I will soon get an error that says "printer busy, aborting print". Once I get this error I have to turn off my printer, un-plug the usb and close cura, wait a few seconds and then re-connect and then I can start a new print. I also got this error after I completed a print and tried to do a second one. I do not know if this is a marlin issue or a cura one.
I just tried to multiply an object in 3.6.8 and cura crashed on me.
That is a different issue being reported here: T5010
Please post there that you were able to recreate that, and do your best to include the same information others have, if you have it.
For this ticket all that is needed is to start a print on a quiver through USB connected to cura, abort it mid-print, and attempt to restart