My seller was
https://www.ebay.de/usr/heybattery26...72.m2749.l2754.
So it is a totally different one.
I suppose the device has a general problem, possibly if it is not used for a while.
It would be interesting to know if other users of the likebook also did not use it for 6-8 weeks and did not have the problem.
What may be special with my device is, that I have put it in a case with a magnetic switch. That is, if I close the case the likebook reacts on the switch and goes into sleep.