Basic informations:
We're using osTicket v1.18.1 with two plugins:

• Help Desk Audit ver. 0.1
• Oauth2 Client ver. 0.6

We've connected to our M365 tenant using Oauth2 plugin without strict match - mailbox using for gathering tickets is shared mailbox.
Fetch frequency is set to 1 minut
Emails per fetch 30 ( we usually fetch 1-5 emails per batch )
Fetched Emails - move to folder XYZ
It's hosted on home.pl hosting and deployed using "autoinstaller".

Issue:
We've noticed that emails are fetched after long time spend in inbox.
Examples:

• Email that was received on 9:42 today come up in osTicket at 10:11
• Email received at 13:06 was fetched at 14:39 the same day
  Ticket raised via web gui come up instantaneously.

Do you have any ideas what should I check? Is there a way to speed it up?
inb4 I have only access to osTicket Admin Panel.