Tax not charged during checkout

[FWS2020]

I just enabled tax on my products and I noticed the following:
- Tax shows on cart on if estimate tax button is used during the checkout stage
- If estimate tax is not used, unregistered users/guests get away without paying tax even if they enter their address

I tried to find the solution for this through this community, alot of people have the same issue but I dont see the solution. I am using Version: 8.1.0.

Any assistance would be much appreciated so that tax is added to unregistered users when checking out after their address is added (tax rates depend on location).

Thanks