Weird automatic transmission behavior [NOT A BUG]

[Austin.S]

While I was driving unmodded Scania R730,it always shift 8th gear direct to 10th gear (skipping 9th gear).
The problem is that if the trailer weighted over 22 ton,the truck doesn't have enough torque to accelerate in 10th gear,so it downshifts to 8th gear and shifts up to 10th after 1 or 2 seconds due to high RPM in 8th gear,and the problem persists.
In other words,it keep shifting between 8 and 10,like 8->10->8->10->8...so on

edit: adaptive automatic transmission was disabled,because it doesn't work well with keyboard

[Blackspots]

Thats just normal adaptive automatic behavior.

[Austin.S]

Thats just normal adaptive automatic behavior.

unfortunately,I wasn't using adaptive automatic transmission

[Driver080]

Not enough torque with a 730 really?

[Austin.S]

Not enough torque with a 730 really?

For 25 ton cargo,yes
The problem are the gear ratio and shifting logic(mainly),what engine doesn't matter
well,I can replace 730 with 500 or 580 in my original post,but does that change anything? The problem get worse with lower power engines

[Cadde]

automatic transmission are generally designed to shift based on your accelerator input.
I assume you are using a keyboard... As such, try mouse accelerator control instead of keyboard.