Yes this is strange Nuendo should jump to the right location each time and eventually drift if the “internal” clocks do not have the same source.
Seems like there is some kind of Jam sync or something that is silently adding this running offset between Logic and Nuendo. Perhaps you could try to use another virtual midi port utility to link the two softwares, actually you are using the default system one if i’m right (i’m not used to the MAC world).
Or you could try to use 9pin sync using a virtual serial port, if Logic can output in this format.