I was looking at this topic (since I’m facing the same issue) and talked to Bitwarden, to which they replied:
“I currently have the Brave browser open on Windows 10 with Bitwarden installed and logged into and 3 tabs open. Monitoring the task manager in Windows shows Brave using 0% CPU, or 1-2% while switching around to different tabs in the browser.”
As for myself, 73% with (27) right beside Brave Browser on Task Manager (3 tabs open)… anyone know how to help?
Version 0.56.12 Chromium: 70.0.3538.77 (Official Build) (64-bit)