I couldn't decipher exactly what you are asking in this case. Are you saying that:
1) You pruned your blockchain and then imported the address; or
2) You imported the address and then pruned the blockchain?
Keep in mind that '-rescan' is disabled in pruned mode (according to 0.12.0 release notes), thus importing an address will not show it's balance IIRC.
Thanks for the response.
1) You pruned your blockchain and then imported the address; or
This. I used importaddress "my-watch-only-address" "" false
With importaddress "my-watch-only-address" I got a "Rescan is ddisabled in pruned mode" error.
I was wondering why would it need a rescan. I thought the full blockchain is needed only for the transaction history.
In case that someone doesn't care about the history, why would he just import an address of private key to check balance?