Extra vertical blue bars on selected tab member view after refreshing page

[Mr Lucky]

The selected tab on the member info page is denoted by a horizontal blue border at the bottom.




However if you refresh the page two more (different color) borders appear at the left and right.



What is this for? It's not possible to inspect via browser inspector as they disappear when you try to inspect.

View attachment Screen Recording 2024-08-18 at 13.19.39.mov
Extra vertical blue bars on selected tab member view after refreshing page

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