laravel 链接达梦数据库，报字符集错误 Malformed UTF-8 characters, possibly incorrectly encoded

当前使用的 Laravel8版本，php 8， DM8

database里已配置

'dm' => [
        'driver'         => 'dm',
        'tns'            => env('DB_TNS', ''),
        'host'           => env('DB_HOST', ''),
        'port'           => env('DB_PORT', '5237'),
        'database'       => env('DB_DATABASE', ''),
        'username'       => env('DB_USERNAME', ''),
        'password'       => env('DB_PASSWORD', ''),
        'charset'        => env('DB_CHARSET', 'UTF-8'),
        'prefix'         => env('DB_PREFIX', ''),
    ],

相关信息也已在.env有配置
可是登录请求后报错

exception
: 
"InvalidArgumentException"
file
: 
"D:\\workspace\\projects\\hongkou_access\\backend\\src\\vendor\\laravel\\framework\\src\\Illuminate\\Http\\JsonResponse.php"
line
: 
91
message
: 
"Malformed UTF-8 characters, possibly incorrectly encoded"

查看了错误是中文 编码为CP936，配置中的UTF-8编码没生效。 求解答