No, you do not have to pay CA tax just because your W-2 says CA - as long as you have established legal residency in FL and are performing your work in FL.

You should not need and a tax attorney to deal with this issue going forward. CA is fairly aggressive in its tax collection, so they may contact you for additional information.

When preparing your 2020 state return, file as a part-year resident of CA and allocate your income as appropriate to CA and FL (there is an interview in the CA state tax program to do this).  If your employer withheld CA state tax for the entire year, you should get a refund of CA tax withheld while a resident of FL.

Your employer can continue reporting your wages as "CA income", but as long as you are physically performing your job in Fl (as a FL resident), you should be able to avoid paying CA tax on your earnings.

Some states have passed "convenience of the employer" legislation which means people in your situation would be liable for state tax where their employer is located. CA hasn't done that (yet), but be aware.  See State income tax considerations for remote employees during COVID-19 for a discussion of this issue. The states that have enacted such a rule include Connecticut, Delaware, Nebraska, New York and Pennsylvania. 

FYI - If you still have A CA driver's license and voter's registration, then you are probably still a CA resident and subject to CA tax on your income, no matter where you work.