Google Chrome Kyber Issues

Hello guys!

I am facing serious problems with Google Chrome Kyber. Specifically on 40F series. I have a couple of firewalls on 3 different versions (7.4.3, 7.4.4 and 7.4.5). Each of them has issues but with different behavior:

Google Kyber Issues

Slowness to open websites or pages that won´t load.

7.4.3 - Google Kyber problem
Which feature is impacting? Web Filter

Solutions:
1. Disable Web filter
2. disable Google Chrome Kyber
3. Adjust tcp-mss-sender and receiver to 1450 in the policy

7.4.4 - Google Kyber problem
Which feature is impacting? Application Control

Solution:
1. Disable Application Control
2. Disable Google Chrome Kyber
Adjusting tcp-mss-sender/receiver doesn´t work

7.4.5 - Google Kyber problem
Which feature is impacting? Application Control

Solution:
1. Disable Application Control
Disabling Google Chrome Kyber doesn´t work
Adjusting tcp-mss-sender/receiver doesn´t work

I am migrating a lot of customers from other vendor to Fortigate with Fortimanager and trying to follow a default firmware version to use to all my customers.

I´m start to think that 7.4 fortiOS isn´t a good idea and I´m a little bit worried about it.

Anyone has these kind of problems?

Maybe it´s worth downgrade to 7.2 version?

Thanks!

Mantovani