Compatibility issue between PT12.8-Tascam US-20x20 and OS Sierra?

[solveigh]

Hi everyone.
My first thread here, mainly because I still haven't found an answer to my issue. I contacted avid tech support about it. They were helpful but the issue is probably on the interface side.
So here's my problem :
I'm using Pro Tools 12.8.2 on a new Macbook Pro with Touch bar (3,1 GHz Intel Core i5 - 8GB Ram).
My audio interface is a TASCAM US-20x20.
It used to work fine on a HP laptop but I changed to the Macbook to have a silent machine.
I have a repeated Error AAE -6101 that happens on a 2 track-session with only 3 plugins on the master track. The song stops all the time because of this error. Nothing changes when I change to 2048 samples. When playing the song, I still have 4gb of free RAM so the problem is not the RAM.
It's just impossible to work.
Thanks to the guys at Avid, we found that the session worked fine in standalone mode (without Tascam connected). When it is in use, the song stops after less than 30 seconds sometimes. Re-installing the driver didn't change anything. Changing sample rates and bits didn't change anything.
I had a reply from Tascam tech support :
"This driver shows no problems on our Sierra test system using a variety of DAWs and other audio softwares.
However, we do not have ProTools installed here. Therefore, we cannot confirm stability with this platform."
I tried to play a song in Ableton Live though the Tascam and it worked fine.
Does anyone have the same problem as mine?
Thanks a lot for your help!