TLS Handshake Failed in SSL VPN access

I am receiving this error when trying to connect via SSL VPN to the portal.

2017-11-25 21:52:18 TCPv4_CLIENT link remote: [AF_INET]XX.XX.XX.XX:443
2017-11-25 21:52:18 MANAGEMENT: >STATE:1511668338,WAIT,,,
2017-11-25 21:52:18 MANAGEMENT: >STATE:1511668338,AUTH,,,
2017-11-25 21:52:18 TLS: Initial packet from [AF_INET]XX.XX.XX.XX:443, sid=7273b871 8de32caf
2017-11-25 21:52:18 VERIFY ERROR: depth=1, error=unable to get issuer certificate: C=NA, O=GlobalSign nv-sa, CN=AlphaSSL CA - SHA256 - G2
2017-11-25 21:52:18 OpenSSL: error:14090086:SSL routines:ssl3_get_server_certificate:certificate verify failed
2017-11-25 21:52:18 TLS_ERROR: BIO read tls_read_plaintext error
2017-11-25 21:52:18 TLS Error: TLS object -> incoming plaintext read error
2017-11-25 21:52:18 TLS Error: TLS handshake failed
2017-11-25 21:52:18 Fatal TLS error (check_tls_errors_co), restarting
2017-11-25 21:52:18 SIGUSR1[soft,tls-error] received, process restarting
2017-11-25 21:52:18 MANAGEMENT: >STATE:1511668338,RECONNECTING,tls-error,,
2017-11-25 21:52:18 MANAGEMENT: CMD 'hold release'

I currently am using a public DNS record on Port 443. I have a CA signed wildcard domain which I'm using
for my VPN certificate. *.domain.com. My VPN is: vpn.domain.com.
I also use this for my portal / reverse proxy and it is verified by browser and a valid certificate.

The above error occurs when I attempt to use this same certificate in my SSL VPN configuration.
If I use a user signed certificate or my self-signed webadmin cert; the SSL connects fine.

Any help is appreciated!