Dozens of studies claim sea level was higher 4,000 to 9,000 years ago

Source:

https://notrickszone.com/2m-higher-holocene-sea-levels/ 

 

Plus a few more published in 2020:

https://notrickszone.com/2021/01/04/huge-database-of-studies-documenting-meters-higher-mid-holocene-sea-levels-swells-again-in-2020/