Elias here with Shopify Support. Thank you for reaching out!
That's a great question! It's a bit hard for me to determine where this message is without being able to see your account or any screenshots. However, the 'Tax included' message can be due to the product not being marked for 'Charge taxes on this product' or the 'Show all prices with tax included ' is enabled in your Tax settings.
To check your products, you'll need to edit the product. Then, will see a checkbox for the 'Charge taxes on this product' in the Pricing section. If you have multiple variants for a specific product, you will need check this for each variant. This field will look something like this:
Alternatively, if the message is not due to the product's pricing section, then you'll want to check your Tax settings. The Tax settings can be found under 'Settings > Taxes', then look for 'Show all prices with tax included' in the Tax calculations section. Here's a screenshot of what it looks like:
Let me know if this helps! If you run into any issues with this, don’t hesitate to let me know in this thread and I'd be happy to take a closer look!
Thanks for following up. I'd be happy take a closer look at your store. I've located your shop and I've sent an authentication email to each of your inboxes. Kindly check your inbox/spam/junk folder in the account owner's email and reply to it. That way, we can proceed with the next steps. Thanks!