When you use G91 for rotating the 4th axis you sometimes end up with it rotated several complete revolutions from zero. Haas has a feature called Quick Rotary G28 which lets you zero the 4th axis to the nearest zero point instead of 'unwinding' all the revolutions.
I cannot remember whether they are a Setting or Parameter that has to be turned on but I think there are two; one is called Quick rotary G28 and the other is Circle Wrap.
An open mind is a virtue...so long as all the common sense has not leaked out.