Ok, being that you were an original investor with Shaban, EDS and BCY, I can assume you have been involved with Bitcoin/XCP since 2015 and probably a bit earlier than that. So hopefully everything I say will be easier to understand for you or easier for you to connect the dots for what I have to offer you. However, that said, if you are not 100% clear on what is said please just ask me to clarify. From what I know of your situation this really won’t be overly technical though.
If you had one address and upon your return to crypto your Passphrase is generating a completely new address now, then I must conclude that your Passphrase is weak and causing a “Collision”. What that is in simple terms is essentially your Passphrase causes two different addresses not ONE distinct address. That is the most obvious reason for this but doesn’t completely explain the rest of the issue. So, Counterparty relies on an abridged version of the BIP39 dictionary to create Passphrases. The standard BIP39 dictionary is 2046 words and Counterwallet’s dictionary only contains 1626 words of the BIP39 dictionary. The chance of a collision occurring with the Counterwallet word list is in the neighborhood of less than 0.0044%. If I had to guess, I would randomly assume your Passphrase of 12 words most likely contains 2 or 3 three letter words Combined with 3 four letter words. That was just a complete guess on the contents of your words, but groups of simple words in mnemonic Passphrases can cause collisions, again very very rarely. That was a serious crash course on collisions by my normal standards. However, I’ll happily get into the details if you are interested, just ask.
That is really the obvious solution to your direct issue. Unfortunately the solution to the missing Coins and Assets is not as simple as that. I feel for you honestly and as completely rare as collisions are, I actually have one myself that occurred in January 2011 for which I sent 14.713 btc to. Long story short, that situation is similar but different because the collision was caused by extremely weak entropy. Now those bitcoin are just gone as there is no way of retrieving them. Your situation is different also because you have hope of recovering your assets. I noticed that the person who committed just prior to this post, mentioned JP’s site for recovering broken Passphrases. That would be my first suggestion for you as well. He did a great job with that recovery tool but keep in mind it won’t unscramble a whole Passphrase and fix it in that manner. Why? Well first off, every single word in the Counterparty dictionary can match up with any other word in the 1626 word dictionary. Unlike, for example, the full BIP39 dictionary word list that has words of which can not be combined with others. If that makes sense. Now on JP’s site what it does is find words that do not belong and points them out. For example, say you are supposed to have “great” as the third word but you entered “greet”, if greet was not in the dictionary it would immediately point it out and show you what possibilities you should try.
If that does not offer the solution, I would help you out. That said though, you should never, never, ever, ever show your Passphrase to anyone, unless on your death bed. So keep that in mind. Now for a case like yours, if you required help where someone would see any part of your Passphrase, then upon finding the solution you must immediately transfer all assets out and into a new secure wallet. Obviously throw the old one away. I’m not implying anything would happen or that all people are bad, but instead you just need to always practice Security in all situations.
Lastly, you mentioned you opened your wallet about 3 months ago, and had an odd feeling. Well there was a low life scammer about 3 months ago phishing the counterwallet.io address however it had the obvious marks to avoid if you ever see this, counterwallet.io/hidhdtducov/, or whatever since I just scribbled letters after the /. If you ever see anything after the / remember to never enter anything into the Passphrase box. Just a tip and a thought I had about 3 months ago.
I hope you figure out the solution to your issue, good luck. If I can be of any assistance to you, please ask. I hope this gave you what you were looking for in the form of an answer. Thx and I apologize for roughly typing this in on my phone. Please try and excuse any errors as I did not proof this prior to hitting “Reply”. Good luck.