If this really is the case, then you still should be able to somehow access your coins.

But as bitmover pointed out, some (at least 1) of your statements must be wrong.

Could you please answer the following questions (again, just to be sure):

Where did you initially generate your seed (electrum on tails?)
Where did you download electrum from? And how did you do it? Did you verify the pgp signature ?
Do your current wallets addresses (on tails) indeed start with 1.. ?
Did you check whether you can copy a random BTC address (preferably starting with 1..) and paste it anywhere without it being tampered with (on your online machine) ?
Your first (small) transaction is also not visible in your tails wallet, correct ?
Did you change any options in electrum? Did you generate a multisig or 2FA wallet ?

I know that these questions are redundant, but something isn't right and we have to figure out what.
[/quote]

bob123,

thank you very much for such substantial explanation! The questions are not redundant and I'm glad to answer them!

1. Where did you initially generate your seed (electrum on tails?) - Yes, it was generated on Electrum on Tails! (I only have problem with wallet on Tail. On Windows works everything properly)

2. Where did you download electrum from? And how did you do it? Did you verify the pgp signature ? -
   1) On Tails it's already preinstalled, but old version, so you have to update manually. To do that - I downloaded the ''Appimage" for Linux on electrum.org. Where as well I found the explanation why my wallet didn't work - it was old!
   And that's where it started instead of just updating it, the guide lines on Tails website say - to delete the wallet; to delete the wallet folder in the wallet; to do this, to do that.... All bullsh!t. In realty just to update the f*cking wallet!
   2) On Windows I downloaded the wallet as well from the website. I didn't verify PGP signature - but I did a transfer from a BTC.com wallet to that one and I transferred it back - worked perfectly! I as well did some transactions now from Electrum (Windows) to Electrum(Tails) - works perfectly too! _____So I think fishing is out of question!_____

3. Do your current wallets addresses (on tails) indeed start with 1.. ? - Yes, all of them, always, even when the wallet was recovered.

4. Did you check whether you can copy a random BTC address (preferably starting with 1..) and paste it anywhere without it being tampered with (on your online machine) ? - Yes, as mentioned before I'm doing transactions without any issues!

5. Your first (small) transaction is also not visible in your tails wallet, correct ? - Correct. In first place I saw it in the wallet on Tails as "pending" but then it changed to "not verified". It was the same wallet as the big transaction (if I'm not wrong), just different address. I just realized it has only 1 output address and it should be the one from my wallet which I copied and pasted! Here it is transaction ID: 888f769c2d2585d1d6f0070f11d5820c249aa895fab983ce3eda7e1a667e7308

6. Did you change any options in electrum? Did you generate a multisig or 2FA wallet ? -
   1)All I changed is: Tools > Preferences > Transactions > checked the box with ''use multiple change address" on both wallets. On Tails as well Block explorer to .onion one.
   2) No multisig or 2FA wallet!

So my opinion is: there is no phishing or clipboard malware or any type of fraud! Since there was an issue with corruption - at least that's what the guide lines on Tails said, I could open the wallet at all, you know etc. - it was recommended to delete the files, reinstall and so on. So now that missing address is in a wallet somewhere. The question is how to get that particular wallet!

Any suggestions?