Lnav is jerking to the right

[Theod]

Make sure you’ve double clicked on the heading of your autopilot to ensure that your listed heading is your actual heading.

LNAV Heading

This was changed in 26.1 so the heading “bug” no longer automatically changes - this is how it works on aircraft in real life. You just need to manually set it so that it matches up if you need to disengage LNAV.