**Describe what's wrong**

```sql
SELECT toTypeName(s), toString(s) FROM
(
 SELECT toFixedString('',32) AS s 
 UNION ALL
 SELECT null AS s 
)
```

this query works in all versions from 19.17 to 21.8, but stop works after 21.9+ 

https://fiddle.clickhouse.com/7bd65b36-a6e6-470a-8bdc-4c98a33ff453
21.8 works

https://fiddle.clickhouse.com/9e40a424-4027-4c7f-bd41-b20935ae9129
21.9 doesn't work
```
Received exception from server (version 21.9.6):
Code: 44. DB::Exception: Received from localhost:9000. DB::Exception: Illegal column Nullable(FixedString(32)) of first argument of function toString. (ILLEGAL_COLUMN)
```

this query works in all versions

```sql
SELECT toTypeName(s), toString(s) FROM
(
 SELECT '' AS s 
 UNION ALL
 SELECT null AS s 
)
```
https://fiddle.clickhouse.com/4f810f03-1644-4eb7-b696-0341b1bbdbc4


**Does it reproduce on recent release?**
Yes, reproduce in all releases 21.9+
ColumnsWithTypeAndName tmp_args;
                if (source_is_nullable)
                    tmp_args = createBlockWithNestedColumns(arguments);
                else
                    tmp_args = arguments;
                const ColumnNullable * nullable_source = nullptr;
                
                if (source_is_nullable)
                {
                    if (arguments.size() != 1)
                        throw Exception("Invalid number of arguments", ErrorCodes::LOGICAL_ERROR);
                    nullable_source = typeid_cast<const ColumnNullable *>(arguments.front().column.get());
                }
                
                auto tmp_res = wrapper(tmp_args, nested_type, nullable_source, input_rows_count);
                
                if (!tmp_res)
                    throw Exception("Couldn't convert " + arguments[0].type->getName() + " to "
                                    + nested_type->getName() + " in " + " prepareRemoveNullable wrapper.", ErrorCodes::LOGICAL_ERROR);
                return wrapInNullable(tmp_res, arguments, nested_type, input_rows_count);
            };
        }
        else if (source_is_nullable)
        {
            
            return [wrapper, skip_not_null_check]
                (ColumnsWithTypeAndName & arguments, const DataTypePtr & result_type, const ColumnNullable *, size_t input_rows_count) -> ColumnPtr
            {
                auto tmp_args = createBlockWithNestedColumns(arguments);
                auto nested_type = removeNullable(result_type);