After upgrade to latest 0.14.0 null values appears for various metrics

[garry-t]

What did you do? upgrade to 0.14.0 What did you expect to see? no null values What did you see instead? Under which circumstances?

Environment Ubuntu 22.04

• System information:

  Linux 5.15.0-57-generic x86_64

• postgres_exporter version:

postgres_exporter, version 0.14.0 (branch: HEAD, revision: c06e57db4e502696ab4e8b8898bb2a59b7b33a59)
  build user:       root@f2337de13240
  build date:       20230920-01:43:49
  go version:       go1.20.8
  platform:         linux/amd64
  tags:             netgo static_build

• postgres_exporter flags:

/opt/prometheus/postgres_exporter/postgres_exporter --collector.long_running_transactions --collector.stat_statements --web.listen-address :9187

• PostgreSQL version:

  13.3

• Logs:

 postgres_exporter[2809843]: ts=2023-11-15T19:50:31.182Z caller=postgres_exporter.go:682 level=error err="Error opening connection to database (user=postgres%20dbname=production%20host=/var/run/postgresql/%20sslmode=disable): driver: bad connection"
level=error msg="collector failed" name=stat_bgwriter duration_seconds=0.397204571 err="sql: database is closed"
:28:45.587Z caller=collector.go:199 level=error msg="collector failed" name=replication_slot duration_seconds=0.397212416 err="sql: database is closed"
:28:45.587Z caller=collector.go:199 level=error msg="collector failed" name=statio_user_tables duration_seconds=0.39728339 err="sql: database is closed"
:28:45.587Z caller=collector.go:199 level=error msg="collector failed" name=stat_statements duration_seconds=0.397285173 err="sql: database is closed"
:28:45.587Z caller=collector.go:199 level=error msg="collector failed" name=replication duration_seconds=0.39728341 err="sql: database is closed"
:28:45.587Z caller=collector.go:199 level=error msg="collector failed" name=long_running_transactions duration_seconds=0.397279512 err="sql: database is closed"
:28:45.587Z caller=collector.go:199 level=error msg="collector failed" name=locks duration_seconds=0.397212446 err="sql: database is closed"
:28:45.587Z caller=collector.go:199 level=error msg="collector failed" name=database duration_seconds=0.397266999 err="sql: database is closed"
:28:45.588Z caller=collector.go:199 level=error msg="collector failed" name=wal duration_seconds=0.397308607 err="sql: database is closed"
:28:45.588Z caller=collector.go:199 level=error msg="collector failed" name=stat_database duration_seconds=0.397292096 err="sql: database is closed"