Besides that, if I make one single dummy transaction just to test the account, all remaining transactions start to appear in all previously mentioned areas - Summary:
Balance sheet report:
Even account’s balance is 0, I would expect to see transactions of that account, because these are there. Also, not showing transactions when account balance is 0 can be very misleading, making me think that there were no transactions associated with that account, while in fact these are. Then I will be required to waste time checking if there actually were no transactions or were. That is not good.
What I am doing wrong? How to make those accounts show transactions even when the balance is 0?
So, it looks like you have entered everything correctly. And what you see is the result of consistent behavior for all other control accounts. If there is no balance, transactions do not show. Remember, control accounts themselves have no balances. Only their subaccounts have balances. So, when PayPal (the actual account) has a balance, that subaccount will show. But its transactions will not. You first have to choose the individual subaccount to see transactions.
When you entered your test transaction, what appears upon drilling down from the Summary is not the transaction, it is the non-zero balance of the PayPal (account) control account, broken down to the PayPal subaccount.
Your situation is cloudier than most, because you have buried the actual PayPal bank account three groups deep in your chart of accounts.
In summary, you cannot expect a transactions list after drilling down on any control account. And, when an element of a control account has a zero balance, you cannot expect it to show as a contribution to the control account’s balance or the balance of the group to which its control account is assigned, because there is no contribution. That means that if you want to see transactions in a bank account, you must drill down on its statement balance (or actual balance) in the Bank Accounts tab.
But I am still puzzled by the absence of the “Empty” notice in your screen shots #4 and #5. Were they just not captured?