Postgresql Upgrade from 10 to 14

Hi Team,

I need some help or suggestions for the below issue. Please provide answers
what to do now. We re in critical position to handle the issue.

Issue: We upgraded postgresql from 10 to 14 version, post to the upgrade ,
queries are running very slower than normal expected time. As well as the
queries are not getting completed . We did vacuum analyze, index recreation
and analyze statements etc but no luck still the job queries are running
slower like 10hrs , 14hrs . So please help what we need to do to fix the
issue.

Actually we have spark scala application that will use JDBC driver to make
connection to the postgresql and then execute the queries. Before upgrade
the same application used to complete in very lesser time like 10mts but
now its taking 14hrs and not getting completed.

Not sure why upgrade making slower in performance. Previously the job used
to complete in lesser time.

Please advise and provide suggestion what inorder to do fix the issue.
Kindly help and waiting for good reply with exact solutions