When I open ex) the Trezor file, I don't see any balance
Then those files are set up incorrectly. Every one of the three multi-sig files should show the same addresses and the same balance when you open them. This probably explains why you cannot currently spend your coins.
In the first instance, I would try creating a brand new Electrum wallet using your two hardware devices and your Electrum seed phrase, and without importing any master public keys/xpubs/ypubs/zpubs. This should create a new 2-of-3 multi-sig wallet which shows your coins, and which you can spend from. This is safe enough to do on your current computer since you are still protected by your hardware wallets. If doing this generates a different wallet with different addresses than your funded 2-of-3 multi-sig, then we have other issues to address before addressing any errors you are experiencing.
How long ago did you set up this multi-sig wallet? Do you remember how you did it? Have you reset either of the hardware wallets since you did it? Have you ever used a passphrase/13th word/25th word/seed extension?
"I would try creating a brand new Electrum wallet using your two hardware devices and your Electrum seed phrase, and without importing any master public keys/xpubs/ypubs/zpubs. This should create a new 2-of-3 multi-sig wallet which shows your coins, and which you can spend from. This is safe enough to do on your current computer since you are still protected by your hardware wallets. If doing this generates a different wallet with different addresses than your funded 2-of-3 multi-sig, then we have other issues to address before addressing any errors you are experiencing."
Unfortunately don't see any balance when I do this
"How long ago did you set up this multi-sig wallet? Do you remember how you did it? Have you reset either of the hardware wallets since you did it? Have you ever used a passphrase/13th word/25th word/seed extension?"
I believe in early 2019
I did it following this guide
https://medium.com/@tiero/how-to-bitcoin-multi-signature-wallet-using-electrum-and-several-ledger-nano-s-225867e3b726I am pretty sure I did the following:
Create 2/3 multi-sig wallet in Electrum
#1 = Electrum (the app)
#2 = import cosigner key from Ledger
#3 = import cosigner key from Trezor
If by resetting hardware wallets, you mean changing the seed, no I did not
"Have you ever used a passphrase/13th word/25th word/seed extension?"
Is this adding a password/extra word when entering your seed somewhere? If so, I didn't use anything like that