Five members of the Synod of the Ecumenical Patriarchate did not sign Tomos, the document that officially recognises the Orthodox Church of Ukraine as independent. That would be almost half out of the 12 members of the Synod.
According to the Orthodox Church of Ukraine, Tomos was signed by all 12 members of the current Synod. All twelve church representatives, who signed the document, are active members of the Synod. The last was renewed on September 1, 2018, according to the standard procedure of the Constantinople Patriarchate. The current Synod will serve until February 28, 2019.
For more information on the tomos of the autocephaly see here.