Weird behaviour when restoring database


I have been trying to restore some lost data into an other existing database and noticed a weird behaviour.

This page explains how to restore data from an healthy database to an existing one with downtimes :

Here’s what I did to reproduce the problem , step by step:

1 - Backup of the healthy database
2 - Restored the healthy database on the faulty instance with the name database_bak

3 - Then I ran this , while connected to database_bak

SELECT * INTO pgwatch2.three_months.:MEASUREMENT FROM /.*/ WHERE time > now() - 4d GROUP BY *

which led me to this error :

ERR: partial write: field type conflict: input field "idle" on measurement "backends" is type float, already exists as type integer dropped=585

Alright, I guess there are some type issues between the backup and the db

show field keys from backends
name: backends
fieldKey                   fieldType
--------                   ---------
active                     integer
av_workers                 integer
background_workers         integer
idle                       integer
idleintransaction          integer
instance_total             integer
longest_autovacuum_seconds integer
longest_query_seconds      integer
longest_session_seconds    integer
longest_tx_seconds         integer
max_connections            integer
max_xmin_age_tx            integer
total                      integer
waiting                    integer

This command did not show any anomalies, all my measurements were integers, both on the backup and faulty database.

Afterwards, I decided to reinsert measurements one by one, and did not see any issues. Everything was copied into the faulty database.

Is there something wrong I am missing with the way I tried to reinsert all the measurements at the same time ?