I did see that guide and I have selected the “Apply tax settings on option prices from WooCommerce->Tax” option. Still, it does not work.
However, if I select “including tax” under the option “Display prices during cart and checkout” from WooCommerce->Tax it starts adding the correct VAT to the PPOM option. The problem with this is I do not want to display including tax.
I did have the PPOM Pro from the client portal installed. I had to “Start migration” to the new version/look and then also check the option PPOM Settings->PPOM Price-> “Apply Tax on fixed/cart fee” in order for it to work. This guide is for the old version it seems. Thank you though. Plugin’s great!