Switch one front tire with a rear tire.
Drive it and if there is no change do the same with the other front tire.
This should eliminate any question about properly balanced tires.
Straight front axles with any worn suspension joints are more sensitive to slightly unbalanced wheels or tires.
Check king pins, bearings, spindles, drag link, tie rod ends...
It can be hard to find a tire place with a good and calibrated balancing machine.
Many tire places think an 'old and slow truck' doesn't even need balancing.
And then you got to find an operator who takes the time to do it right.
