I keep seeing threads of incorrect passphases and seeds after an update
I believe the best solutions is:
1)a separate hardware wallet from a different manufacturer
never update the firmware on the new wallet
use this new HW as a seed and passphase tester
then reset it once tested (have a separate ADA & DOGE wallet send a small amount out and the a few in 1 from another HW & 1 from an exchange)
Hi @ffvddfed3,
I can confirm that your seed can be wiped from the Trezor device if something goes wrong during the firmware update (this is a security feature that is meant to protect your device against physical attacks if the attacker tries to install unofficial firmware on your device). More information can be found at https://trezor.io/support/a/firmware-update-issues
Anyway, it is highly recommended to keep the firmware in your device up to date in order to preserve security and privacy.
Actually, it is only important to be sure that your recovery seed backup is correct. There is a simple way to verify it. You can check that the recovery seed stored in your Trezor device matches your recovery seed backup (you can check your seed before every firmware update if you want):
for Trezor Model One: https://trezor.io/learn/a/test-recovery-seed-on-trezor-model-one
for Trezor Model T: https://trezor.io/learn/a/test-recovery-seed-on-trezor-model-t
Passphrase cannot be wiped as it is not stored in Trezor. You need to be absolutely sure that you use the correct passphrase, even if you are going to use different wallets.
You can read more about passphrase here: https://trezor.io/learn/a/passphrases-and-hidden-wallets
and also in this post on our Trezor Blog: Passphrase — the Ultimate Protection for Your Accounts | by SatoshiLabs | Trezor Blog
Ok
So they could be a bug within the seed word 1 & 24 are swapped round
The update wipes the seed or correct the problem
Therefore, when you attempt to recover, it is incorrect
A separate hardware wallet is needed to prevent against potential faulty individual device
There is no bug that can swap your recovery seed words. Once the recovery seed is created, it will always stay the same (the same words in the same order). As mentioned in a previous post, you can easily test your recovery seed backup. If it is correct (matches the recovery seed stored in your Trezor), you will be always able to recover your wallet with this recovery seed backup. There is no need to use another wallet if you are sure your recovery seed backup is correct.
You can find information on how to perform recovery process in this article:
for Trezor Model One: https://trezor.io/learn/a/recover-wallet-on-trezor-model-one
for Trezor Model T: https://trezor.io/learn/a/recover-wallet-on-trezor-model-t
So how do you explain
after a Firmware update
PIN codes not working then the seed backup is incorrect?
First, please keep in mind that PIN is used only to unlock the Trezor device. The PIN is not used to generate your recovery seed. You can find more information on PIN at https://trezor.io/learn/a/pin-protection-on-trezor-devices
If your device doesn’t accept the PIN, it means that you using an incorrect one. If you are not able to enter the correct PIN the only solution is to factory reset the device, recover it with your recovery seed backup and set a new PIN. You can find information on how to perform a factory reset and set a new PIN in this article: https://trezor.io/support/a/how-to-reset-your-pin
If the check of recovery seed backup is incorrect, your recovery seed backup is different from the recovery seed stored in your Trezor.
If the recovery process is not successful, your recovery seed backup is not correct.
May I ask you if you have some specific issues (invalid PIN, recovery seed backup check was not successful or you are not able to successfully perform recovery process)?
No, I have not had a problem
But from all the posts I see created, I believe having a separate hardware wallet with an undated firmware as a fallback that you have tested with your seed and passphrase bear in mind, you can always wipe the device after testing
Let’s say a firmware update had been causing a problem, and somehow it is fixed, therefore using the other device to regain access(only if you can’t recover)
This is why I advise people to
A) check the seed and passpase several time(to rule out human error)
even if you’re not intending to use ada or doge set up a separate wallet for them to be used as like a testbed(if you’re going to cold store them, have this in a separate wallet on the device)
That way, when you add these coins after recovering, you can cross reference wallet, addresses and transaction IDs
B) periodically, test, your seed and passphase, even if everything is working correctly(there is never an incorrect seed/passphase. ONLY A MISSTYPED/INCORRECTLY COPIED BACKUP which When using incorrect, backup will take you different wallet addresses)
This is all unnecessary if you have the seed phrase also called recovery seed. Because with a seed phrase you’re able to restore a wallet. If you also use a password with the seed phrase than you also need that to restore a password protected wallet also called hidden wallet in the Trevor Suite.
Most people here who cannot access their wallet never wrote it down or have a backup whereby you punch in your seed phrase in a metal plate. You always need to write down the seed phrase and the password (if you use one).
This is not a problem if you have the (correct) seed phrase. And by correct, the one of the wallet you want to recover. Most people who lost their wallet assume they use the correct seed phrase or don’t check which seed phrases belong to which wallet. Normally you need one, but some wallets make additional seed phrases like third party wallet used in conjunction with a hardware wallet, like Metamask or Exodus. Some users don’t understand which wallet they use even in those applications (software wallet - also called hot wallet).
so… put all you faith and funds in pure faith 
what if a passphase charter was miss interrupted on the first HW example: , .
these are very easy to miss judge
HW wallet one breaks yet your funds are now lost forever, for the sake of a cheaper wallet to use as a tester 