Been there many times
Variable ratio boxes must be dead center to work properly, if you are correcting too much have the alignment done again.
That little adjusting plug in steering box can make things go bad quickly if not adjusted properly and does ruin the box.
Steering sensor on column may need replacement but only a good shop can tell you this. I've even had some fools say just remove the sensors connector and don't worry about it, cause they don't understand it.
I've changed out many boxes on my rig, but think the problem really is bad tech's doing the change out the parts until they get the right one, or maybe just an alignment was only thing needed.
One recent issue was adjusting cam washer on upper control arm was broken, alignment shop did not detect it I finally did, changed shops again.
99 GMC SUB, 2500, 4x4, 6.5 TD (F) #H32 enhanced blk, Phaser timing set, B&D IC, 3" ATS exh, K&N w/prefilter, 4WD NVG 246, 4L80E kevlar Transgo off road/tow mods/B&M supercooler, 14 FF MagTec w/locker 3.42:1, 9.25" IFS frt/diff 3.42:1 w/ARB locker, AutoMeter Boost & pre-turbo pyro meter, 12,000 lb hydro winch, Warn classic bumper w/brushguard & diesel scoop, Max E-torq Stage 3, hi pop inj, oil bypass sys, on board air comp for front ARB locker & tire inflation, DynaView driving/auto-cornering lts, DZ nerfs, A/T 285/75/16 SilentArmor 3750 lb rated on 3750 lb rated Alcoa, 3 IP drivers 2 r spares.