Issue with Allo Isolator, Hifiberry Digi+ pro

Hi, there,

After having used a Raspberry Pi 3, Isolator and a Digi + for a while, I decided to do the upgrade to a Digi + pro and I can’t get it to work. With the normal Digi + it all works fine in master mode and on every voltage I set between 6v-15v on my linear power supply, but as soon as I go to the pro there is no sound coming out anymore.
The pro directly on the Pi works fine, but as soon as the isolator comes in, no more. I tested both coaxial and toslink.
During testing I tried a cheap mini dac together with a simple power cube and suddenly it plays, but when I connect my normal dac (Terdak V2.1 TDA-1543 NOS) it doesn’t work. Also as soon as I change the power supply from the block to the linear power supply together with the cheap dac, it looks like the clock is not correct anymore and everything starts to stutter and plays slower, this happens at whatever voltage.

So there is a problem with the Dac and with the power supply that only plays up as soon as I put the pro on it.

No body who can help me?