Are you importing to a staging site or live site? Do you have a Google API key?
I know some developers do not bother getting one for a dev site,Not having one will have a big impact on how fast the geocoding is processed. Googlke is throttling back and slowing down the geocoding if no API key.
Google has been warning about having APIS since before the grandfather date of June 22, 2016. every iteration or change they make has become more restrictive. (Of course they want everyone to add a pay as you go credit card :just in case” you exceed the daily query limits. ) Without more info about your site configuration etc it is hard to tell.