Is this working as intended?

[Klausewitz]

So I, as Germany, was fighting Italy and Hungary, joined together in the PACT OF ROME.
Britain was fighting them too along with all their allies.
Then I declared war on Yugoslavia.
They joined the Pact of Rome.
And then they allied with Britain against me despite their alliance fighting them?
Is that WaD?

 

[DarthVader201661]

I don’t think that should happen unless they were guaranteed by the UK or of the other faction members.

 

[SchwarzKatze]

They joined the Pact of Rome.
And then they allied with Britain against me despite their alliance fighting them?

A country cannot be in two alliances (factions) at the same time. Can you elaborate what you mean by "allied"?

 

[Klausewitz]

A country cannot be in two alliances (factions) at the same time. Can you elaborate what you mean by "allied"?

They fought alongside the allies (who fought the factions they were in, though they had not been called).

 

[SchwarzKatze]

They fought alongside the allies (who fought the factions they were in, though they had not been called).

Oh, Allies with capital A.

If Yugoslavia was guaranteed by one of the Allies, then this is perfectly normal. Guarantees will be activated regardless if they are in the same faction or not.