Since the Soyuz MS-10 in October will only have two persons aboard, it would be a great opportunity for space science on the ISS to let Richard Arnold continue his mission for another 6 months until the return of Soyuz MS-10 (exactly the same situation as before with Peggy Whitson). Are there negotiations with Roscosmos on this?
Richard Arnold returned with the rest of his Soyuz MS-08 crew after 196 days in space.
Since then, no crew was or is planned to stay for at least a year. Christina Koch stayed the longest during this period, 328 days. (Scott Kelly stayed 340 days, but that was prior to this question.) Two of the future Soyuz MS-19 crew are planned to stay 354 days.