1. "Gap Limit" issue... if the original accounts were setup using the Chrome App and NOT Ledger Live, it's possible the coins were sent to an address past the gap limit or even a change address (if selected from the drop down menu instead of using "receive" tab)
2. Valid but incorrect seed... there have been instances in the past where users have managed to get seeds confused and use a wallet for a while but have a seed written down that doesn't match that particular wallet. Not likely given OPs claim that this is their only wallet.
3. Multiple "Accounts" within Ledger... 1st account is currently empty, so Ledger Live might not see if coins were sent to "2nd" accounts. Could test using Electrum and specifying 2nd or subsequent accounts in derivation path (ie. m/49'/0'/1')
4. "Forked" accounts? I know that there were all sorts of crazy things happening when the BCH fork first happened with the "split" accounts in Ledger Chrome App... I'm not sure if Ledger Live still looks for these? Was the device originally configured/setup within Chrome App or Ledger Live?
3. That's an interesting one. I did have 2 accounts, although each did have coins in them. I'll try to edit the derivation path to your specs and see how that goes.
As for 1 and 4 they the accounts were set up using a Ledger Live app and not a chrome one.
2. Has been suggested a lot although I am 99% certain that I have the right seeds, I'll keep that in mind as a possibility. If all else fails I'll have to do a btrecovery or something.
I appreciate the suggestions.