Welcome. There is one true, Holy Synod of the Ethiopian Orthodox Tewahido Church that rests in Addis Abeba, Ethiopia and H.H. Abune Pawlos presides as the one, legal patriarch.
Since the time of the Derg's Regime, there has been a lot of chicaneries on behalf of the socialists' regime, in a plot to destroy the Orthodox Tewahido Church(es). These anti-Christs have also furthered the conflict with Eritrea and Ethiopia.
Anyway, after the death of HH Abune Tekle Hayimanot, who did not succumb to the antics of the Derg; the Derg installed a puppet patriarch (Abune Merkurios), who worked along with the regime. When the Derg fell to a 'rebel' force, lead by the TPLF and other forces. Once the communists were ousted, the Synod of the EOTC decided to summon all of the EOTC's archbishops and bishops (at home and abroad) to Ethiopia in order to decide the fate of Abune Merkurios--whether he should remain patriarch or be stripped of his title, because of the heinous acts that he committed with the Derg.
A letter was presented to the Synod by Abune Merkurios saying that he was ill and that he participated in crimes against his fellow Ethiopians, and that he was not worthy to retain the position of patriarch. He then fled to Kenya and eventually ended-up in the US. Before and after the unanimous election of Abune Pawlos, the Holy Synod sought to reconcile Abune Merkurios with the Church, but under-the-influence of renegade bishops, Abune Merkurios declined to return to the jurisdiction of the Mother Church in Ethiopia.
Within the last year, Abune Merkurios and his 'synod in exile' have consecrated more than 15 bishops and continue to establish churches in the US, Canada and Europe, under this so-called synod-in-exile. They've issued letters, denouncing the Abune Pawlos and the Holy Synod in Addis Abeba. They also curse other Ethiopian factions that remain without bishops.
The Holy Synod of the EOTC also issued anathemas upon the 'synod in exile' within the last year, because of these consecrations, abandonment of bishoprics and various declarations.
There are (unfortunately) so-called independent Ethiopian Orthodox Tewahido Churches, that are patriarch-less and bishop-less. They function as an Ethiopian Orthodox Community, but seclude themselves in regards to a hierarchy.
I don't believe that any of the factions are dogmatically heretics, but perhaps they are accused of heresy.
I hope that may have helped.