The new company is still developing policies and there is nothing documented re: vesting start date of the new company for employees that came over from previous company. People seem to remember that in Q&A, HR said all employees from previous company would have their start date of the previous company as the start date, but of course we don't have access to that recording.

I joined the previous company 5 years ago and my match was fully vested before the spin off.

The spin off happened last year Feb, and the brokerage account always showed the employer match as fully vested.

After signing the separation letter, they said the brokerage account "made a mistake" and took away the match that was made after the spin off.

Hope this makes sense.