SRX

My wife's beater 96 A4 Q 2.8 5 speed manual, last couple weeks trans driveline had a slight noise only when in gear under any load, depress the clutch quiet, release sounded like a gear rumble, however all gears work fine, clutch is good, yesterday my wife went down our driveway and the car just locked up, a mechanical bind. I managed to reverse it but could feel the issue, still goes into every gear, check all Cv shafts & drive shaft all seem good

I am wondering if the center Torsen has collapsed ?? any clues knowledge let me know. I trying to find another trans right now unless this is a common issue and can be repaired