How about Spain in central Europe, how did that happend?
That was a normal PU actually, Spain and Hungary were allies and had a RM. Hungary passed its dynasty on to Spain and got PU'd a bit later. A couple of years before this screenshot, you would have also seen a Portuguese Austria but I released them again.
Yet another weird PU thing with this game was this: Spain, Portugal, Muscovy and me (Hungary too but they're gone as I said) all have Rurikovich monarchs. I had Spain and Portugal under me and then saw that I could claim the Muscovite throne as well, which I promptly did. He was allied with France and had a RM with them too but France has a de Bourbon monarch. So I'm warring Muscovy and France but then all of a sudden Muscovy drops out of the war and I only get the message that I lost my claim on their throne, which can happen during a throne claim war but it'll continue normally. So I checked what happened: Turns out that even though I claimed the throne and was of the same dynasty as Muscovy AND had more prestige than France, France still got Muscovy in a PU. Lucky nation indeed!
Now the war continued, me vs France, the war for the Muscovite throne. I won the war and actually got France AND Muscovy in a PU under me, which didn't really make sense but hey, I was happy.
Ofc, instant karma happened and France turned revolutionairy so I waited out the truce and went with the revolutionairy CB since I know you can't restore a PU with a republic unless you want to keep doing that over and over every election. Plus the restoration of union CB was available long enough for a second war after this one. So I turned them back to France but lost my restoration of union CB anyways. I was pretty pissed but hey, I shouldn't have been able to PU them anyway.
Very weird game!