Your screenshot shows the number at 1.9cm and the text at 2.5cm. This means that IF the numbers take up more than 6mm the text won't be able to sit at the 2.5 mark and it will have to instead move over to the next default tab stop position.

If you add enough text on one of those paragraphs so that it wraps to the next line you will see how the indent position is too close to the start of the number.

So 'counter-intuitively' the fix is to increase the 'text indent at' number to something that allows the digits and periods string to finish.

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Andrew Lockton
Chrysalis Design, Melbourne Australia