Murky Octograb bug vs Tracer (watched replay to confirm)

I’m a level 718 Murky main and played a QM game last night on Dragon Shire.

ISSUE - 2x in the same game, Murky’s Octograb ult failed to land and went on 50 sec CD.

1st time
Tracer was all alone with no one within 3 screens. She blinked just as I Octgrabbed. Ult went on 50 sec CD (not 10 sec CD). I became UNSTOPPABLE for 3 secs, but wasn’t rooted in place.

2nd time
Same issue. Tracer blinks and ult goes on 50 sec CD without landing. This time the ult makes the sound that it landed, but she’s not stunned and I didn’t become UNSTOPPABLE for 3 sec and was free to move. Octograb is on 50 sec CD.