Was Ethiopia was still in union with the Byzantine Orthodox even after Chalcedon?

Saint Gregentios of Ethiopia Omiritia, who died in 552, was a Byzantine Orthodox Bishop shepherding the flock in the Empire of Axum.

Saint Gregentios was taught and ordained a deacon in Rome, a notably Chalcedonian area at the time of his life.

After St Elesbaan had conquered Yemen, he requested a Bishop to care for the Orthodox Christians who were persecuted there under the Jewish warlords.

St Gregentios received a vision that he must become a Bishop. He visited Cnople and Emperor Justin I before going to Alexandria where even the Patriarch had a vision to ordain Gregentios a bishop.

Notably during this time, there was no Bishop of Ethiopia proper, only Gregentios.