Application pools are set up as "HS_SharedAppPool_Classic_x32" for all sites after migration of one Windows server to another.
To fix application pools:
Download on CP box domain_selector.sh and run under "cpanel" user as shown bellow:
~# ./domain_selector.sh <l.server_id>
#<l.server_id>is id of the logical server your domains have migrated to.
Download Pool_Fixer.ps1 on windows box you have migrated to.
Run Pool_fixer as shown on example bellow:
PS C:\Users\Administrator> C:\script.ps1 example.txt