Latest is Hotfix 3 - version 4.1.83.6620 (10 October 2020)
All is fine on mine, no re-download.
GoG install on Win10 Pro 64bit.
Manually checked for updates, nothing new since, last patch was few days ago.
Must be on your end, try to repair, not always downloading the amount is says, just verifying that amount.
Already was a similar post, replied here
http://forums.larian.com/ubbthreads.php?ubb=showflat&Number=695002#Post695002will quote so don't have to type again:
"Are you sure it's downloading? Open task manger and look at traffic, or even better
on Win10/8/7 create a shortcut and name it "Resource Monitor", traget is
C:\Windows\System32\perfmon.exe /res
and check network traffic, because the "downloading" message in could just mean "checking file integrity and repairing by re-downloading those missing or corrupted""