Octoprint and Anycubic Mega S communication problem in vase mode

In normal operation everything works fine as expected. However, as soon as I print something in vase-mode (Cura: spiralized outer contour) printing is perfect until it is done. Then the head moves where it should but the bed gets stuck with stepper motor on and a communication error is reported.

This happens every time, repeatable, with my setup. I have never seen any communication error in normal printing so far.

Not a really big deal as the print is already finished and good but I wonder whether it is an issue with the printer firmware (still original Anycubic) or something else. Does it also happen with other printers?

Didn't post it in "get help" as to me this isn't something I can't live with....