On iOs 12.5.3 in Brave browser 1.24 (126.96.36.199)
In my “normal” mode I have some tabs opened.
I was in a private mode. Multi tabs was opened too in the private mode.
I close the private navigation mode, by touch the “Private” button on the bottom left corner.
I did’nt interact with tabs in normal mode before closing the app.
Later I opened the browser.
Favicon of the first tab in normal mode was replaced by favicon of the first previous tab from private mode.
Some kind of similitude with Thumbnail bug from private to non-private tabs