This has been the best Thanksgiving day gift I have ever received (especially significant given the fact that (i) American's don't give gifts other than food at Thanksgiving and (ii) I have only been celebrating American Thanksgiving for a few years - the Canadian feast is in October). In any event here is the wonderful information provided by Professor Brock who notes that there is only a Latin tr. of the relevant part of the Zuqnin Chron: the English translation only cover the later parts. The passage is on p.124 of Chabot's edition, vol I:
At this time the heresy of Sabellius sprang up. Sabellius rose up against the Church at this time and said: The Trinity has a single qnoma [usually = hypostasis], and for this reason Mary is the birth-giver of the Trinity, and the Cross also is of the Trinity. A Synod of 43 bishops gathered against/concerning him to Ancyra of Galatia, and reached a decision: they anathematized him and ejected him from the Church because he was not willing to turn back from the position he had taken
Brock also looked in the other large chron. (ad annum 1234) but found nothing there. He said I could try the other small Chronicles in Chron.Minora, but most of them don't cover the time of Hadrian. The source history of the different chronicles is quite complicated: for the Zuqnin Chron, there is a monograph by W Witakowski (1987). One other critically significant insight that Brock provided was noting that "the corruption of 'NQR' to NQY' (Ancyra to Nicaea) would not be all that difficult in Syriac script." At last we have an explanation for that little problem. Now on to other things.