Dear Justin,
Thank you for your quick reply.
Unfortunately, the server having this issue is an Azure Flexible Server.
Upgrades are managed by Azure, I will have to wait until they release the version 13.7.
Is there a procedure to replicate the database and preserve the bug.
My attempts with pg_dump/psql failed (the bug vanishes).
If so then I can clone the faulty database and upgrade it on a newer version.
Best regards,
Landercy Jean