Hi developers! It would seem that pgAdmin4 pastes OID numbers as numeric literals instead of string literals, if this report can be trusted:
https://dba.stackexchange.com/questions/247119/unable-to-output-data-from-tables-in-pgadmin-due-to-missing-oid-operator Leads to sneaky errors with OIDs beyond 2^31. Details in the added answer there. I did not recreate the issue as its hard to fake those OIDs. Do you want me to add a bug report in Redmine? Regards Erwin