Here is the correct way:
And, here was my failed attempt so that you do not repeat same mistake as I did:
When moving wallet from v1 dapp to v2 dapp, I added account in v2 dapp ,and out of unknowing I clicked mnemonic aka seedphrase (than should-be raw original seed), and added seed from my old chainx address. I did it 2 times out of despair not having same address created in v2 as of v1.
I used keypair crypto type to ed25519 protocol, which was correct.
I was basically trying to migrate using chainX private key from chainX extension.
In process, I saved .json file (.json filename is same as created new address in v2 wallet) ,and since I did it with same mnemonic, wallet address became same in both cases, which unfortunately was not as intended v1 add.
and since I did not do raw original seed but mnemonic, it assumed new address to be created, which obviously was different from original chainX address in v1 dapp.
but later I corrected myself to change it to raw seed where I put put private key from orig. v1 wallet. Then, v2 address became same as v1 ,hence balance assets were correctly migrated.
(Lesson from this mistake can be implement in polkadot.js.org's repeated issue of new kusama address being created unintentionally
now what does this mean? It means chainX mainnet has been successfully upgraded to Substrate 2.0, which will adopt polkadot's new hybrid consensus mechanism and enable on-chain governance functions. The 2.0 mainnet will be compatible with all Polkadot functions.
MEANS whatever polkadot dapps allow user to do like staking, governance + many more, is in https://dapp-v2.chainx.org/#/accounts also.