Still waiting for further tracking data to confirm this, but this seems an unprecedented step by Russia if correct. I don't think it quite violates the Outer Space Treaty though (but IANAL)
@avrnz New TLEs show that K2612 made a manuever on Oct 16 and is now stationkeeping within 5 km or less of ICEYE X36. To my knowledge this is the first LEO rendezvous of two active satellites where the owner of one of the sats did not give approval.