Understanding Bitcoin Cash SV split

[CompNsci]

I am trying to understand better what happened technically with the Bitcoin Cash SV (BCH-SV) split.

What is puzzling me is that I recently created a Bitcoin Cash (BCH) wallet with an old private key which had bitcoin at the time of the BCH split in 2017. It showed the balance of BCH, which I then sent to another bitcoin cash address in a different wallet (wallet #2).

Now when I try and load that old key into a BCH-SV wallet, it shows the movement of the BCH and says that there is no BCH-SV balance available.

When I import from wallet #2 into a new BCH-SV wallet, is says that I can split the BCH-SV off.

I am not understanding what is happening here in terms of the blockchains. Why would a transfer of the BCH at a date after the BCH-SV split in 2018 result in BCH-SV being available? Are they somehow marking transactions on the BCH blockchain as either BCH alone or BCH and BCH-SV being moved?

[Rickorick]

When bsv forked off from bch, it didn’t add replay protection. What this means is that, any transaction created in one blockchain, would be mirrored in the order. In order to prevent this from constantly happening, you’ll have to split the bsv from the bch before you can use it properly.

[Lizzylove1]

When bsv forked off from bch, it didn’t add replay protection. What this means is that, any transaction created in one blockchain, would be mirrored in the order. In order to prevent this from constantly happening, you’ll have to split the bsv from the bch before you can use it properly.

This is even more technical, how does a layman split this himself? what I understand then was that some wallet and exchanges supported this split while some were supporting BCHABC.

[Ucy]

When bsv forked off from bch, it didn’t add replay protection. What this means is that, any transaction created in one blockchain, would be mirrored in the order. In order to prevent this from constantly happening, you’ll have to split the bsv from the bch before you can use it properly.

This is even more technical, how does a layman split this himself? what I understand then was that some wallet and exchanges supported this split while some were supporting BCHABC.

You probably should ask bch community here:
https://memo.cash/all. That is where you will likely get a quick and satisfactory answer. Rickorick gave you a good answer, I think.   
You should check out their community if you want the technical aspect answered to your sanctification: https://memo.cash/all

[batang_bitcoin]

If you find it hard to get into it. You should look for some other tutorials that's make it easier for you to claim the fork. Exodus made this easier because you just have to send your BCH into their wallet and let them claim the BSV for you.
https://support.exodus.io/article/994-how-do-i-claim-bsv-in-exodus
But since you have already sent it to another wallet, check the electron cash tutorial. I'm not really technical with these forks.