**How to reproduce**
Clickhouse server 20.13.1.5273
```
CREATE TABLE default.test
(
`key` UInt32,
`ts` DateTime CODEC(DoubleDelta, LZ4),
`db_time` DateTime DEFAULT now() COMMENT 'spout-ignore' CODEC(DoubleDelta, LZ4)
)
ENGINE = MergeTree
PARTITION BY toStartOfTenMinutes(db_time)
ORDER BY (key, ts)
TTL db_time + toIntervalHour(3)
SETTINGS index_granularity = 8192, merge_with_ttl_timeout = 3600, min_rows_for_compact_part = 1000000, min_bytes_for_compact_part = 200000000, in_memory_parts_enable_wal = 0;


INSERT INTO test(key, ts) SELECT number % 1000, now() + intDiv(number,1000) FROM numbers(500);

SELECT * FROM test;
500 rows in set. Elapsed: 0.003 sec.

DETACH TABLE test;

ATTACH TABLE test;

SELECT * FROM test;

0 rows in set. Elapsed: 0.002 sec.
```

**Expected behavior**
Clickhouse would flush parts on disk.
FutureMergedMutatedPartPtr future_part_,
    size_t total_size,
    StorageMergeTree & storage_,
    const StorageMetadataPtr & metadata_snapshot,
    bool is_mutation)
    : future_part(future_part_), storage(storage_)
{
    
    
    if (is_mutation)
        reserved_space = storage.tryReserveSpace(total_size, future_part->parts[0]->volume);
    else
    {
        IMergeTreeDataPart::TTLInfos ttl_infos;
        size_t max_volume_index = 0;
        for (auto & part_ptr : future_part->parts)
        {
            ttl_infos.update(part_ptr->ttl_infos);
            max_volume_index = std::max(max_volume_index, storage.getStoragePolicy()->getVolumeIndexByDisk(part_ptr->volume->getDisk()));
        }
        reserved_space = storage.balancedReservation(
            metadata_snapshot,
            total_size,
            max_volume_index,
            future_part->name,
            future_part->part_info,
            future_part->parts,
            &tagger,
            &ttl_infos);
        if (!reserved_space)