Does it make more sense what I tried to solve my issue?
Honestly, no, but you shouldn't give up. The more you talk about it, the more your chances to recover them.
1. I started with bitcoin core around 2011 up to 2015. Private keys and addresses generated those years. Left the addresses with some coins and never had a look at it again until last year November.
For how many addresses are we talking about?
2. I tried to get access to my wallets in bitcoin core but private keys wont regenerate spendable wallets. Did not even show addresses.
This doesn't make sense. Why should private keys regenerate wallets? Do you mean they don't give the same addresses once imported to another wallet?
3. Downloaded Electrum 4.1.5 and import private keys in Electrum. Took some time but gave me a watching only wallet but with my original Addresses the way I left it with the coins still there.
There are lots of things that I can't explain such as:
- Why did it take so long to sync?
- Why did it return you a watch-only wallet if you imported private keys?
There's probably something done wrong during the importation as I've never seen this case before. If you're importing valid private keys in the correct format, such as:
p2pkh:KzoyMdabwRwfWy98HQzrhdXFw6bcUCJKK9RR32VpkYcS4WtoUHKB
You should be getting a non-watch-only wallet.
4. Tried to import the private key in Blockchain but it gave me a different address. No coins in it (Obviously). Same different address with Exodus.
Note that if your private key starts with K, then these are compressed addresses and since your time period was 2011-2015, those addresses should be starting with 1. Blockchain dot com or Exodus may return you addresses that either start with 3 or bc1.
What you're looking is called a legacy address. Again, those that start with 1. Don't mess with wallet software that don't have the option of importing legacy addresses, it's a waste of time.
5. Went back to Electrum again. Gave me watching only address again when importing private keys with original addresses.
Have you tried importing one private key at a time?
6. Never tried to import any address in any of these platforms.
Good, stick with Electrum, it's more than fine.