Tax name and value not appearing on invoice pdf

I have the placeholders for tax name and tax value on my invoice template but they do not appear on the pdf. There is a blank line instead beneath the sub-total, then the total appears which has correctly added in the tax. I have another invoice template that has this section entered exactly the same and it works as it should. The only difference between the two templates is an extra column to show a discount.

I would appreciate some help on this ASAP. Thanks.

Cathy