I encountered two bugs:
(i) Persistent Items do nothing (e.g. the vial that increases your health don´t work)
verified: Blood of the fallen, Staff of the warmage, Diamond pendant, magical coinpunch, ... i wonder which ones do work the more i test
(ii) with some of them you have to buy them every game others are persistent:
(the persistant ones i have bought before the update after christmas, so maybe they work because they are from an older version)
Items which are persistent: swift anklet, brilliant bauble and the three minion buffing ones