OP, it is nice that you have come up with this article. I am not a tech guru, but at least I have been in the space for a little while now, and what I know most is that the higher the amount one puts as a transaction fee, the faster the confirmation, but sometimes it seems there is no competition on the mining block rewards (please spare my choice of words), as one can set a little transaction fee and it is quickly confirmed. Another thing I have also discovered is that transactions are quickly confirmed at night, within the time from 11:00 PM to 03:00 AM, but not as quickly as it is during the day, and I believe it is likely the reason being that people do more transactions during the day than at night, or are there any other reasons for it?

Lastly, I had an experience with the Trust Wallet app when I tried to transfer some Bitcoin to another wallet, but whenever I tried to do such, I always got an error message as UTXO ERROR, even when I increased the fee, the same response I got, and I did this repeatedly, thinking it was a network error. I checked for a wallet update, and the wallet version is up to date. I had to download another wallet and import the private key into the wallet, and I did my transaction without adding any fees. This made me wonder what really happened because I thought that if I increased the fee, the transaction would scale up, but it did not. Can you explain what really happened there?