When performing crash recovery, we all know that there are three phases to recover: rollforward, open, rollback. During the rollback phase, if there is a large tx that requires rollback, smon takes care of this (possibly delegating the work to parallel slaves if using fast_start_parallel_rollback).
We are having an issue that we cannot allocate sort space until smon completes this rollback. Please do not respond with 'smon is cleaning up your temporary segment' because we are using a locally managed temporary tablespace. So smon should not have any work to do to prepare for a sort. The query requiring a disk sort is being done on an object that does not have any tx rollback occurring.
The shadow process for the query that is requiring a disk sort is waiting on 'sort segment request', but all of the parameters for the wait are 0: