I go to Ivanstead and a qUard runs up to arrest me, but as a thieves guild member he says I can go, but then he attacks me anyway. WTF

I think I got some explanations:

-You were seen transforming, thus causing you to get a bounty.
-You don't have Dawnguard and you are a stage 4 vamp, thus causing everyone to attack you.
-You had a previous bounty.

If that doesn't explain anything, I don't know.

never transformed in Ivanstead and I am a VL

Does the bounty of a city can carry over to another one?