VAT no longer added (without changing any settings)

-- url of the page with the problem -- : grandestampa.com/shop/account-carrello/cassa
-- HikaShop version -- : 3.4.0
-- Joomla version -- : 3.8.8.
-- PHP version -- : 7.2.4.
-- Browser(s) name and version -- : all
-- Error-message(debug-mod must be tuned on) -- : none

Hi,
the settings are not to show taxes until the cart on checkout and here today the taxes are sometimes added and other times they are not.
I tried an example of a client and before adding the address and VAT number, the VAT was correctly shown. After clicking on 'proceed' the VAT was no longer shown and also not calculated.
This is rather urgent because I did not change any settings for a long time now.
Just tried updating joomla and hikashop but the same problem is still there.
Hope you can help?
Thanks!

Have now done more tests and found out the tax category for this specific product was for electronic goods and services (wrong).
Guess that is why depending on the address the VAT was added or not.
Anyway ... problem solved!
Only comment from my side would be that it would be better not to have the this tax category automatically chosen to prevent this mistake ... but it is my mistake!