Continuing to step5, I added execution_butler to the submission script in order to avoid any more DB connection problems:
There were two errors, one in each of forcedPhotDiffOnDiaObjects and forcedPhotCcdOnDiaObjects. A new job, mergeExecutionButler, seemingly failed (according to bps report). However, grepping through the logs doesn't immediately uncover any errors (that I can see at least), and the mergeExecutionButler.5197569.out file says that 174079 files were transferred successfully. So, I'm not sure why bps report is claiming that this job has failed.
Path the the submission: /scratch/brendal4/bps-gen3-rc2/submit/HSC/runs/RC2/w_2021_38/