I take it from your post that they have not been winning positions.
Not even sure about that, but the other day MU was giving .5 -107.50 with Indosoccer and Aston Villa receiving .5 +110 with Pointbet. Be aware these two books are as a matter of speaking in the same building and have their offices next to each other, so I asked another bookie that is right next to them too about this arbitrage situation and he then warned me to be careful with Pointbet.