git hangs with --separate-git-dir

Windows 10 PC large project 300GB 500,000 files mix of binary and text assets.

cd /d D:\myproject git init --separate-git-dir=F:\myproject.git git add *

Git runs for a little while then hangs and does some really bad things to the OS as well. it seems impossible to kill git.exe even with administrator priviledges. f: drive ends up locked and any other process, such as explorer that try to look at it also hang you cannot log out without hanging or even restart This then requires a hard power cycle to fix.

100% reproducable.

running git init without --separate-git-dir and git add * works fine (takes 3 hours,.. but works) then I can move the .git dir to f: and reinit with --separate-git-dir and that works. So this seems to only be a problem for the initial init.