Possible Bug in POS Ver 5?

In Latest VER 5:

I created a master tax record called GST with On Net Total, Rate=10% and do not select “Tax included in Basic Rate”

I create a service item with a value of $100

I then create a POS sales invoice. Everything works in the invoice as expected. I click once on the item and my POS invoice immediately updates and shows 1 x Item @ $100 and the grand total becomes $110.
So far so good.

I then modify the same master tax record called GST, but Select “Tax included in Basic Rate” which is what I want.

Now when I create a POS sales invoice I click on the item once. The POS invoice shows that I have added 1 item but the item value and the grand total value show up as $0.
I then add the same $100 item again.
The POS invoice shows that I have added 2 x items and now my item value and the grand total value show up as $100. Not the correct $200.

Can someone test to confirm that this is a bug and not just my setup?

Thanks

Hello,

Thanks for the detailed explanation of the query. I tried replicating tax-inclusive-pos-invoice issue in my test account. It worked just fine.

Though I found issue in the POS Invoice print format, and have created Github Issue for the same.

https://github.com/frappe/erpnext/issues/3138