I have Brave installed on a Win 10 desktop using Classic Shell + Display Fusion Pro and Autohide taskbars on my 3 monitor installation.
In this configuration the current (up-to-date) version of Brave interferes with the displaying of the taskbar. It will appear for a second and then disappear again. Closing Brave fixes the problem, when it occurs. This is not a problem I encounter when running Firefox or Chrome, or both Firefox and Chrome at the same time.
Update Channel Release
OS Platform Microsoft Windows
OS Release 10.0.15063
OS Architecture x64