I believe that your settings is OK, when your Gyro Gain function is unassigned in the software you are controlling Rudder Gain in the software, not in the transmitter.

For beginner it is easier so you can stay with it.

You can increase your Gyro Gain even more, until you see any difference. It should be as high as possible until you will see tail oscillations (during pitch pump or fast forward flight).

What is your helicopter and tail servo? I can help you with correct values for Rudder Delay and Piro Consistency which are very important.

Thank you for the info.

Unfortunately this servo is not constructed for rudder usage. Unfortunately these servos are not behaving too well even on the cyclic (they are fine for flybar helicopter as cyclic servos).
Generally I do not recommend to use any Savox or Align Micro servo, because there is no coreless motor. Thus you are risking failure even if your flying is not acrobatics.

You have to set maximally 60Hz for these servos and use Rudder Revomix to make it work to some extent.

Well, you can type everything on the web.
Unfortunately from our experience there are servos with the same cost, but performance is few times better.

There is pure DC motor, that can be burned in flybarless helicopters - this is by design. For some pilots it is working for months, but if I can recommend, there are really much better servos. You can see the difference just immediately in precision and speed and especially in the flight.

Usually rudder servos should be at least 0.07s/60° and motor have to be Coreless. Mostly all digital servos are Coreless, except Micro servos. Micro servos are equipped very often with DC motor which is the reason, why it look like that bigger helicopters are more stable and precise. In reality your 450 can fly as stable as 700-size helicopter but servos that are behaving similarly to standard size are very expensive. For example MKS DS95/DS95i.

But if you are using these servos and you are satisfied, then I believe it should work and there is rather other issue.

Have you other helicopter that is same and this one just does not work?

Great.

Can you attach your settings from all 3 banks, please? (3 files)

If you are changing between banks you should clearly see in the diagnostic tab, that Rudder Gain is changing too. Respecively Rudder Gain in the Sensor tab should equal to the diagnostic tab.