When you add a new empty tab, the toolbar would flash white.
Likewise, deleting empty tabs would do the same.
Perhaps it is related to this: https://orionfeedback.org/d/7070-swiping-between-two-start-page-tabs-is-laggy
See video
I expect there to be no flashes upon opening and deleting empty tabs.
TestFlight 1.3.8 (9) (WebKit 8618.1.15.10.15)
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