I too have been having a similar problem with a particular plotmaker file.
It has three linked PLN files which randomly swap drawings between them in plotmaker. eg, import 'floor plan building A' and you get 'floor plan Building B'.
next issue is that the pmk files that show up (they were supposed to be drawing views) come up with error ans the status code, and no amount of reinserting them helps.
opening the PLN file on my computer and re-saving it also bares no effect.
I find that i have to delete the link in plotmaker, close the file, and start again.
we are running all the latest panther setup (server and terminal) and the latest building of ArchiCAD 9 NZ.
Karl
Cheers,
Karl Barker.
27" iMac 3.6 Ghz Intel Core i9
32 Gig Ram
Mac OSX 10.14.6
AC 5.5 - AC22 (NZE)