Incorrect results were returned

## Bug Report

Please answer these questions before submitting your issue. Thanks!

### 1. Minimal reproduce step (Required)

```
DROP DATABASE IF EXISTS test;
CREATE DATABASE test;
USE test;
CREATE TABLE `t0` (
`c0` tinytext
) ENGINE=MyISAM ;
CREATE TABLE `t1` (
`c0` bigint DEFAULT NULL,
`c2` float DEFAULT NULL,
KEY `i0` (`c0`)
) ENGINE=MyISAM ;
REPLACE LOW_PRIORITY INTO t0(c0) VALUES("7574176379748798164");
INSERT DELAYED INTO t1(c2, c0) VALUES(NULL, '7574176379748798164');
INSERT DELAYED INTO t1(c2, c0) VALUES(NULL, '7574176379748798464');
```

SELECT ALL t0.c0,t1.c0,t1.c2 FROM t0 inner JOIN t1 on t0.c0 = t1.c0 ;

### 2. What did you expect to see? (Required)
```
c0 |c0 |c2|
-------------------+-------------------+--+
7574176379748798164|7574176379748798164| |
```

### 3. What did you see instead (Required)

```
c0 |c0 |c2|
-------------------+-------------------+--+
7574176379748798164|7574176379748798464| |
7574176379748798164|7574176379748798164| |
```

### 4. What is your TiDB version? (Required)
Release Version: v8.5.5
Edition: Community
Git Commit Hash: 1fa258b833ff113883beeba40bc130be7ce66610
Git Branch: HEAD
UTC Build Time: 2026-01-14 22:19:19
GoVersion: go1.25.5
Race Enabled: false
Check Table Before Drop: false
Store: tikv