Assembly and part property files get mixed up

Since we upgraded form SW2016 to SW2017 we experience problems with property tab files assigned to parts.

We made our property tab files for both assembly's and parts last year using the property tab builder 2015, and both files have different filenames

When i select a part in an assembly with a left mouse click sometimes the taskbar displayes the assembly property tab files (ASMPRP) and sometimes the part property tab file (PRTPRP)

This is quite erratic,sometimes it shows at first the asmprp. other times it shows at first the prtprp, when clicking the left mouse button.

When it is showing the prtprp at first with the left mouse button, the moment i click the part with the right mouse button or when i open the file, the custum properties in the task plane switch the the asmprp. file

reassigning the prtprp file the part does, not seem to fix this problem.

does anyone experience this problem as well?

Many thanks in advance.

SolidworksParts And Features