Long wait for Brave to come up

Brave takes up to 15 minutes to pull up and sometimes it won’t activate at all. Any ideas? Thanks

First thing first :
start by cleaning up all your browsing data.
Just avoid deleting password and identities stuffs.

If the clean up is not enough, start investigate :
check wich plugins start with the Browser and took the most ressources. Use both task managers from Brave and computer for comparison.