Open Ticket Slow In Custom List

Hi everyone hope you could help me with this one.
We are using RT v 4.4.1-3+deb9u3 (Debian) & PostgreSql database.

  • CPU 6x 2.66Ghz
  • RAM 6Go

Our problem is that opening a ticket from the General list is quick(2sec) but openning a ticket from a new/custom list it take almost 8 sec.

We did try to create a new list and add one ticket. It’s still slow opening the ticket.
But if we take the same ticket and send it to General list to be open it’s actually really fast afterward.

We did try to disable the parameter UseSQLForACLChecks but no change.

We also checked rights on list to check if it’s different from general list but no luck.

We have this problem since we moved from version 3 of RT.

Thank you by advance for your help.