Index Corrupted ?

Hi,

I've a strange problem with my upgrade of postgresql 13 (Previously 9.5).
I've two machines Server and Dev :

Server
CENTOS 7
LANG=en_US.UTF-8
LC_CTYPE="en_US.UTF-8"
LC_NUMERIC="en_US.UTF-8"
LC_TIME="en_US.UTF-8"
LC_COLLATE="en_US.UTF-8"
LC_MONETARY="en_US.UTF-8"
LC_MESSAGES="en_US.UTF-8"
LC_PAPER="en_US.UTF-8"
LC_NAME="en_US.UTF-8"
LC_ADDRESS="en_US.UTF-8"
LC_TELEPHONE="en_US.UTF-8"
LC_MEASUREMENT="en_US.UTF-8"
LC_IDENTIFICATION="en_US.UTF-8"
LC_ALL=
Postgresql 13.4
Encoding UTF8
Collation en_US.TF8
CharacterType en_US.UTF8

Dev
Windows 10 English
Postgresql 13.4
Restore via pg_base_backup + wals reintegration standby.signal
Encoding UTF8
Collation en_US.UTF8
CharacterType en_US.UTF8

Here is my problem :

Server
select * from table where indexed_column = 'XXX' => 1 Row
select * from table where indexed_column like 'XXX' => 1 Row

Dev
select * from table where indexed_column = 'XXX' => 0 Row. Strange ???
select * from table where indexed_column like 'XXX' => 1 Row
reindex index indexed_column;
select * from table where indexed_column = 'XXX' => 1 Row. It's working ...

I've tried to reindex production database but it has not resolved anything.

Have you some ideas ?

Thanks

Sebastien