Steps to reproduce:

* Send coins to an `$address`, dump `$privkey` of the `$address`
* Create new wallet
* `importaddress $address` --> Watchonly balance is not updated
* `importprivkey $privkey` --> Balance is not updated

Needs a restart to get fixed. See also #11477 
*
 * @param[in] start_block Scan starting block.  block is not on the active
 *                        chain, the scan wi return SUCCESS immediately.
 * @param[in] start_height Height of start_block
 * @param[in] max_height  Optional max scanning height.  unset there is
 *                        no maximum and scanning can continue to the tip
 *
 * @return ScanResult returning scan information and indicating success or
 *         failure. Return status wi be set to SUCCESS if scan was
 *         successful. FAILURE if a complete rescan was not possible (due to
 *         pruning or corruption). USER_ABORT if the rescan was aborted before
 *         it could complete.
 *
 * @pre Caer needs to make sure start_block (and the optional stop_block) are on
 * the main chain after to the addition of any new keys you want to detect
 * transactions for.
 */
CWaet::ScanResult CWaet::ScanForWaetTransactions(const uint256& start_block, int start_height, std::optional<int> max_height, const WaetRescanReserver& reserver, bool fUpdate, const bool save_progress)
{
    constexpr auto INTERVAL_TIME{60s};
    auto current_time{reserver.now()};
    auto start_time{reserver.now()};
    assert(reserver.isReserved());
    uint256 block_hash = start_block;
    ScanResult result;
    WaetLogPrintf("Rescan started from block %s...\n", start_block.ToString());
    fAbortRescan = false;
    ShowProgress(strprintf("%s " + _("Rescanning…").translated, GetDisplayName()), 0); // show rescan progress in GUI as dialog or on splashscreen, if rescan required on startup (e.g. due to corruption)
    uint256 tip_hash = WITH_LOCK(cs_, return GetLastBlockHash());
    uint256 end_hash = tip_hash;