Database stats ( pg_stat_database.stats_reset ) get reset on daily basis - why?

Hello,

I have noticed recently that our databases (ie most but not all) have their
stats reset on daily basis:

select count(case when stats_reset > (now() - interval '1 day') then 1 else
null end) db_reset_cnt, count(*) db_total_cnt from pg_stat_database;
db_reset_cnt | db_total_cnt
--------------+--------------
77 | 157

Furthermore, the archiver stats also get reset:

select stats_reset from pg_stat_archiver;
stats_reset
-------------------------------
2024-11-21 13:52:35.864855+00

Some facts:
- PostgreSQL v13.16 on Linux Ubuntu 20.04
- There's no evidence in the logs that any pg_stat_reset* functions have
been executed
name | setting
----------------------------+---------
log_min_duration_statement | 0
log_statement | all
- we don't have any user procs with a pg_stat_reset call
- the timestamps of the reset across databases are sometimes close to each
other, but not always

Anyone has any insight on what could be doing this daily stats reset, or
perhaps how to find the root cause?

Regards,
Steeve