Hello @anotherconvert
are you comfortable with using some argument to start your brave with just for one time then you remove it
restart your windows
create a a folder in any place you like it
right click on your brave shortcut icon then properties then click on shortcut then on target filed after the " add one space then write the folowing --user-data-dir=c:\foo
you can replace c:\foo with the location to the folder you created earlier
then click ok then start brave
it will start like if it was a new profile and make sure to turn off the continu running in back ground as caldercay said then after 1 min close brave
then check that all brave process is stopped then
go remove the --user-data-dir=c:\foo that you write earlier then start brave it will load your old profile
now check if this help or you still have the same issue
hope that help and have a nice day 