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How do I get the sum of hours:minutes in MS Excel in the status bar and in a formula if the cells come in with a text format?

I know that there are questions around that are much the same, like Sum the number of hours in Excel, which asks you to format [h]:mm, which I do and it still does not work.
Also not so far is How do ‘Sum’ time in decimals for result in hours and minutes in Excel?.

I have an export of a timesheet:

begin – end – break – working time ([h]:mm)

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and I want to see the sum of the time in the status bar if I mark some of the “working time” cells, like the two 00:45 that should show 01:30 as the sum.

Yet, I can only see the number of cells in the status bar:

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What is more, even if I sum the two cells up in a SUM formula, it returns 00:00:

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If I write down the values in new cells, the formatting works, they are also aligned to the right, as they should:

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Thus, the other numbers are understood as text even if I format them as [h]:mm, you see this from their alignment to the left.

How do I format the [h]:mm (hh:mm) cells so that I see the sum in the status bar, and how can I sum them up in a formula?