WP mail SMTP -Failed to connect to server: (0)

I have a problem to send email in wordpress website contact form.
I use contact form 7 for contact form and WP mail SMTP for mail server connect setting.,
My website testing server can received email from contact form 7 without WP mail SMTP setting.
But production server cannot received email although showed “Thank you” message.
So, I set up SMTP setting using plugin.
It also still fail to received email from contact form. It has error message as shown below.
Please give me some advice to solve this problem.,
Thanks.

Versions:
WordPress: 5.7.2
WordPress MS: No
PHP: 7.0.33
WP Mail SMTP: 2.7.0

Params:
Mailer: smtp
Constants: No
ErrorInfo: SMTP connect() failed. https://github.com/PHPMailer/PHPMailer/wiki/Troubleshooting
Host: mailhost.com.mm
Port: 465
SMTPSecure: ssl
SMTPAutoTLS: bool(true)
SMTPAuth: bool(true)

Server:
OpenSSL: OpenSSL 1.0.2k-fips 26 Jan 2017
Apache.mod_security: No

Debug:
Mailer: Other SMTP
SMTP connect() failed. https://github.com/PHPMailer/PHPMailer/wiki/Troubleshooting

SMTP Debug:
2021-05-27 02:07:10 Connection: opening to ssl://mailhost.com.mm:465, timeout=300, options=array()

2021-05-27 02:07:10 Connection failed. Error #2: failed loading cafile stream: 

> /etc/ssl/bcm-email-tls.pem ‘ [/var/www/html/mywebsite/wp-includes/PHPMailer/SMTP.php line 392]

2021-05-27 02:07:10 Connection failed. Error #2: stream_socket_client(): Failed to enable crypto [/var/www/html/mywebsite/wp-includes/PHPMailer/SMTP.php line 392]

2021-05-27 02:07:10 Connection failed. Error #2: stream_socket_client(): unable to connect to ssl://maihost.com.mm:465 (Unknown error) [/var/www/html/mywebsite/wp-includes/PHPMailer/SMTP.php line 392]

2021-05-27 02:07:10 SMTP ERROR: Failed to connect to server: (0)

SMTP connect() failed. https://github.com/PHPMailer/PHPMailer/wiki/Troubleshooting`