Price with and without tax (moms)

Could you post a screenshot of the listing of tax rules accessible via the menu System->Taxation ?
Maybe you have some restrictions on your taxes preventing them to be applicable to the product.

I see that you limited the tax to individuals and to the zone sverige. On the main tab of the configuration, do you have the "Default address type" option set to individual ? Do you have the option "Main tax zone" set to sverige ?

So, it's working now ?

Great

The more you set restrictions on your tax rules the more you have to have your settings right.

If you have a tax rule limited to your country but that the main tax isn't your country, the tax won't be applied. It will only be applied to the cart once you register or login with an address in that country.

Same for the customer type restriction. If you have a tax rule limited to a customer type but that the default customer type isn't this one, the tax won't be applied. It will only be applied to the cart once you register or login and that the system can categorize your address as a company (you need to fill the company field) or an individual.

Then you have the tax category: if the product doesn't belong to the tax category of the rule, the rule won't be applied.
The tax rule also need to be published.

Create a new tax rule, select a tax rate and a tax category, and set it to published and leave the other fields to the default value and save it. There won't be any limitation on the zone nor on the customer type. You will just have to affect the tax category to the product for the rule to be applied to the product prices.

There is indeed a bug in the system when no zone is set in the tax rule.
We were able to replicate the problem on our end and fix.
Around line 145 of the file administrator/components/com_hikashop/classes/currency.php, if you replace the code

}
			$calculated[$key]=$tax;
		}
		return $calculated[$key];

else{
					foreach($taxPlans as $taxPlan){
						if(empty($taxPlan->zone_namekey)){
							$tax = floatval(@$taxPlan->tax_rate);
						}
					}
				}
			}
			$calculated[$key]=$tax;
		}
		return $calculated[$key];