MD state tax withholding question

I am resident of Florida. I graduated college in May 2020. I accepted a full time position with a company located in Maryland outside DC. I was to relocate to the DC Metro area for my position and in the initial stages of my hiring the company setup my HR profile based on the premise that I would be working in the MD location.
With Covid, the company had all employees work from home and told me I would begin my employment from my residence in Florida. Since June, I have been residing and working remotely from my FL residence and I have not moved to Maryland due to Covid and the distribution of the vaccine. 
Based on the above situation (which I understand is not unique to me):  1) was it correct or incorrect to have MD state income tax withheld? 2) should I have updated my state tax withholding back in June/July 2020 with the company to reflect the state of Florida wage tax withholding instead of the state of Maryland due to not being a resident of Maryland during all of 2020? ) should I update my 2021 state tax withholding with the company to reflect the state of Florida wage tax withholding and change it to the state of Maryland once I become a resident of Maryland sometime in 2021?  
Although I am a resident of FL my work location is in MD but I am not sure if I should have had MD state tax withheld from my wages or not (since June 15th through today the MD state tax has been withheld)? If the MD state tax should not have been withheld then what do I need to do to amend and correct? Or if MD state tax was correctly withheld, could you explain why? and if so, how do I file a MD state tax return?