how can I remove hidden line-spacing formatting?

Often when I copy text from the web into a LO document, some hidden material affects the line-spacing in the copy - and I cannot find a way to remove it. Format > Paragraph shows everything zero, and single line-spacing.

Select text and press Ctrl+M.

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Paste as unformatted text.

It is probably in a table.

Use View>Formatting Marks to see what is really present.