I then transferred the full balance back from Coinbase which showed up correctly in Ledger Live both on my Macbook and on my phone.
About 2 weeks ago I wanted to sell off a portion of the balance. However, each time I tried to transfer to Coinbase I received an error message.
Can you remember what the error message was? I am a little concerned here that your Ledger Live was still showing your old accounts and had not synced up properly to your new accounts. If this is the case, there is a chance you have sent your coins to an address from your old accounts, in which case they would be lost unless you can find the original seed phrase.
Being impatient, I thought maybe a reset of the Nano S would help fix the problem. First I installed the app on the Nano S called "Recovery Check" and confirmed that the recovery phrase I had written down (the newer one after the firmware update) was indeed the correct one. So I wiped out the Nano S and set up from the recovery phrase.
If the seed phrase confirmed correctly, then it is correct.
However, now the BTC balance in Ledger Live on the Macbook is shown as zero. It still shows the original balance on the phone but I don't guess that means much.
Compare the addresses between Ledger Live on the Macbook and Ledger Live on your phone. Do they match?
I had also tried before using the seed generator website (offline) but can anyone advise what to do with all of the information generated and how I can tie this to my specific wallet to confirm the transfer was done? I'm sure that's oversimplifying things but I'm just looking for a way to confirm I transferred to the right place.
With the Ian Coleman site, you should (offline!) enter your seed phrase in the top box entitled "BIP39 Mnemonic". Scroll down to where it says "Derivation Path", and select "BIP84" (assuming you transferred your coins back to a native segwit (bc1) address). Then scroll down to where it says "Derived Addresses", and check if any of those addresses match the address where your funds were sent. If not, then try pressing the button entitled "more rows" at the bottom, and check up to say 50 or 100 addresses. If still not, then scroll back up to where it says "Derived Addresses", change the value in the field "Account" from 0 to 1, and check another 50 or so addresses. If still no match, change the 1 to 2, and repeat. I'd check up to say 5 just to be sure.