Hetman Sahaydachniy (U130) is the ship in question.
https://en.wikipedia.org/wiki/Ukrain...niy_%28U130%29
No, she did not defect.
The navy chief did, reportedly for USD200,000 and tried convincing others to defect too, without success. All the ships still remain under Ukrainian control as far as I know. That may change any minute though.
In other news another RT news anchor could not put up with the lies they were made to say out loud.
That's two in two days. At this rate they will soon have noone left to speak all that rubbish.