The server package contains GxInspect_Intf. A plugin built as a package that contains the unit too cannot be loaded alongside it (duplicate unit name), and two such plugins clash with each other.
So a package plugin has to copy GxInspect_Intf and GxInspect_Locate under names of its own; the GUIDs are what match, not the unit names. README.md ("Finding a running server from another module") and the readme in plugin/ say so. DLL experts like GExperts are not affected.
It is worth considering whether renaming can be made unnecessary, e.g. an include file holding the declarations, which each side wraps in a unit named after itself.