Slitherine

I believe there may be a bug in version 4 as, in one game I was involved in, three units of Spanish guerrillas spawned outside the boundaries of Spanish Morocco into what was then French Morocco.
Can someone have a look at this please?

Not a bug. Spain received part of French Morocco as part of Spanish Morocco when they joined the Axis. So the core owner changed. Think of it as annexation similar to Transylvania changing from Romanian to Hungarian control.