Kenworth Clarion Stereo FM issues, sound cuts in and out

Hi there, new to the Forum but with a real head scratcher.

I have an 09 Kenworth and has given me grief with the stereo since I purchased it last year.

The only time the stereo works 100% crisp and uninterrupted is when I play music through my phone via bluetooth.

Now to the real issue, and the symptoms I've noticed through out the months.

-FM selected on stereo, no 'Chhhhhh' sound, total silence - SiriuxXM not working via FM channel OR AUX
-When I move truck ahead 1ft. all of a sudden receives FM 'Chhhhh' sound and music works via FM & Aux.
-then just cuts out again
-Sometimes when I move my body, arms around picks signal up for a split second, then cuts out again
-With antenna swinging very staticy connection.
-Just started cutting out when going down the road and turning steering wheel to the right
-Sometimes FM works for 2 weeks straight, then all of a sudden giving me grief for days
-Stereo cuts in and out in cloudy weather, and especially bad when raining and wiper blades are going
-If FM receives signal and I talk on CB radio, stereo cuts out to normal FM 'Chhhh" sound, only when transmitting signal, not while receiving
-When I remove stereo while connected, sometimes receives quick signal then cuts out again, dead silence

What I have tried so far...

-Clean antenna base with sandpaper
-Disconnect stereo and blow dust out, clean antenna end that goes into stereo, rewired ground on stereo plug, also check other connections nothing unusual
-Remove dash and check wires above steering wheel, nothing appeared in contact with steering shaft
-Wiggled stereo wires & antenna cable hoping it would make a difference, no change.
-Turn off other electronics inside the truck, without any luck.
-all antennas on truck are opposite side of each other.
-Tried positioning antenna differently before tightening (has a small allen screw)

Thoughts?...

To me it seems like a frequency interference issue, but why does it work sometimes then for weeks without any major hickups, but other days I can't listen to the stereo at all, all day, as it cuts in and out 100x in a song.

Also, why would SiriusXM not work via the AUX cord, even tho FM isn't receiving any signal and by that I mean not even a crackling sound, dead quiet, only works if FM goes Chhhhhhh, and at that point SiriusXM also works on FM frequency & Aux.

Very frustrating.