using 14.5 pg_upgrade on version 10.18 clusters reports unexpected error occasionally

Dear sirs,

Here I am reporting an unexpected error in the course using version 14.5 pg_upgrade tool to upgrade some version 10.18 clusters.
In pg_upgrade_dump_1.log, the following content is collected.
Up to now this problem has been found in 3 database clusters out of around 500.

The PostgreSQL 14.5 binary tool is built using Visual Studio 2015 target to x64 architecture.
The launch to the pg_upgrade tool is done through Windows command prompt, by setting the PGUSER and PGPASSWORD environment variable before the command calling pg_upgrade with proper folders.

I see the collected error as unexpected because this only happened to "template1" database, which is an internal database.
In the same instance, there are records to other databases where pg_restore command runs successfully without error.

I also attached an archive of some other collected logs files generated by pg_upgrade tool in the same call instance when the errors are reported.

Please see if it is feasible to start with investigation to resolve reported problem such that pg_ugprade tool can upgrade database clusters without unexpected errors.

Best regards,
Ken

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command: "C:/Program Files/Exactal/CostXSvr/PostgreSQL/bin/pg_dump" --port 50432 --username postgres --schema-only --quote-all-identifiers --binary-upgrade --format=custom  --file="pg_upgrade_dump_1.custom" ^"dbname^=template1^" >> "pg_upgrade_dump_1.log" 2>&1

command: "C:/Program Files/Exactal/CostXSvr/PostgreSQL/bin/pg_restore" --port 50432 --username postgres --clean --create --exit-on-error --verbose --dbname postgres "pg_upgrade_dump_1.custom" >> "pg_upgrade_dump_1.log" 2>&1
pg_restore: connecting to database for restore
pg_restore: error: connection to server at "localhost" (::1), port 50432 failed: FATAL:  password authentication failed for user "postgres"