Veering at start, but not middle

Hi Everyone.

I have my system working almost perfectly. Pretty arrow straight drilling, however I have a problem.

I line myself up with the AB line at the start of a run, off I go, but even if I sit dead on the line, I press my steer switch and AOG veers me off 12 - 20cm from th line before bringing me bak again.
If I drive manually for the first 20 metres, then press steer swtch, it works fine.

Aquire look ahead is at 3.5, hold look ahead at 2.

Makes no difference if aquire look ahead is from 2.5 to 5.

5.7.2, pcbV2.

It could be a heading error. If it is using more imu than gps it can take a couple of meters to correct. When you stop and are lined up, does the tractor line up with the ab line on the display?

Yeah it lines up with the ab.

I am using 90% IMU though because i have a lot of hills. This field is fairly flat though, Ill try turning it down to 70.

The setting in the photo is for the heading. And adjusting it shouldn’t effect the roll/ level. On the next page is the roll filter,

Ah yes, ok. Well that does perhaps make sense. Sometikes when lining up, the tractor icon is sitting at an angle to the ab line when im actually driving straight. Not when the problem described happens, but its perhaps not noticable.

Ill turn it down to 70/30 tomorrow and give it a try.

100% was the heading. Thanks.