I was on a Tier 2 visa for 2 years in the UK. However, I had to leave because my sponsor lost his license. My sponsor was an umbrella company and at the time I didn’t know it was wrong practice according to UKVI ( I know there is a lot of discussion around this

1. When I checked UK government Tier 2 sponsor’s list I could see my sponsor on January 23rd but had been downgraded to B rating. I left the UK on 3rd March in the same year. Therefore, I don’t think I have overstayed because Tier B means current employees visas are still valid. Is that correct?
2. I also want to know whether there is any penalty for employees in this scenario? Such as stopping them from entering the UK again on a work visa.
Thanks in Advance.