V1 stops running BGP but all other routers inject BGP routes into OSPF.
The destination address (2614:9fca......) is made known to V1 via LSA. However, why is the shortest path V1 -> V2?
When V3 learns the route to S via IBGP from V2/V4, what is the OSPF distance according to V3? Should it be External + Internal = 21 + 2 = 23?