The split view tab is clearly being drawn at full window width in the background if it has not being resized yet with the splitter, switching to/away from it causes a resize event and subsequent loss of PiP window (Bug 1667458).
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The split view tab is clearly being drawn at full window width in the background if it has not been resized yet with the splitter, switching to/away from it causes a resize event and subsequent loss of PiP window (Bug 1667458).