This one developed rather quickly, which is a shame, because it is not over anything relevant to faith, such as theology, doctrine, or worship https://www.reuters.com/article/us-ukraine-religion-russia-idUSKCN1LU2I8

The Russian Orthodox Church’s Holy Synod ruling body convened on Friday to consider how to respond as the Ukrainian Orthodox Church has courted Constantinople to formally make it a self-governing body independent of Moscow. [...]

Vladimir Legoida, a Russian Church spokesman, said the Holy Synod had decided to suspend its participation in all structures chaired or co-chaired by representatives of the Patriarchate of Constantinople.

It is also suspending all services with top priests of the Patriarchate of Constantinople and will not commemorate the Ecumenical Patriarch Bartholomew I in its services, Legoida wrote on social media, summarizing the outcome of the meeting.