Google Dissapproved Ads

For a while now I have been getting some ads dissapproved for price but the prices are correct and it stumped me.

I have nailed it down to it is just the products that dont have any tax. In the UK we dont charge tax on safety boots, so when I add the boot to the website, the price is non taxable...fine.

when I add the product to the merchant centre they always come back incorrect price even though the price shows correct in the merchant centre as to what matches the website.

Has anyone had this before, I use the simtech json addon, maybe that has something to do with what google crawls sees?

Most of my prododucts on the site use the £10.00 (£12.00 incl vat)
these dissapproved ones just show £10.00 and nothing else, is google looking for the btacketed price maybe?