The spendable funds ought to begin being mirrored within the steadiness at any time when the transaction is processed whereas your node is conscious of the personal key. Since your pockets is already displaying you the transaction, apparently the important thing was current when the transaction was processed. I might recommend to attend for the preliminary synchronization to complete, throughout rescans and sync the pockets should still be displaying outdated info till it has caught up with the chaintip.
Usually, a node will routinely rescan the blockchain after importing a key (until you disable it explicitly, e.g. since you need to import a number of keys earlier than rescanning as soon as). If the important thing’s creation date is thought, it would solely scan the blockchain after that date.