OpenVPN woring on all but ubuntu systems

I have a mikrotik rb3011 running openvpn server.
This works for mikrotik - mikrotik tunneling, gentoo - mikrotik, mac - mikrotik and windows - mikrotik.
However, ubuntu - mikrotik returns “error=unsupported certificate purpose”

On gentoo I’ve tested client versions 2.4.2, 2.4.4 and 2.4.6. All works.
On ubuntu I’ve tested version is 2.4.4.

Both the mac and ubuntu got their config file copied from the gentoo client.
I suspect there is some default config on ubuntu that makes the running config on this client differ from the others, despite identical config files. Does anyone have an idea of what needs to be done differently in ubuntu?

Client config

Thanks,
https://diceus.com/dedicated-java-developer/

dev tun
proto tcp-client

remote server.example.local 1194

tls-client

#user nobody
#group nogroup

ca /configs/etc/openvpn/cert_export_ovpn-ca.crt

#comp-lzo # Do not use compression.

# More reliable detection when a system loses its connection.
ping 15
ping-restart 45
ping-timer-rem
persist-tun
persist-key

mute-replay-warnings

verb 3

cipher BF-CBC
auth SHA1
pull

auth-user-pass /configs/etc/openvpn/auth.cfg

Client log

TCP_CLIENT link remote: [AF_INET]xx.xx.xx.xx:1194
 TLS: Initial packet from [AF_INET]xx.xx.xx.xx:1194, sid=f39e6cb9 1d26383b
 VERIFY ERROR: depth=0, error=unsupported certificate purpose: CN=ovpn-ca
 OpenSSL: error:1416F086:SSL routines:tls_process_server_certificate:certificate verify failed
 TLS_ERROR: BIO read tls_read_plaintext error
 TLS Error: TLS object -> incoming plaintext read error
 TLS Error: TLS handshake failed
 Fatal TLS error (check_tls_errors_co), restarting
 SIGUSR1[soft,tls-error] received, process restarting
 Restart pause, 300 second(s)

mikrotik server config

/interface ovpn-server server
set certificate=ovpn-ca cipher=blowfish128,aes128,aes192,aes256 default-profile=vpn-impact enabled=yes netmask=19

Looks like you set the ca certificate for the openvpn server. Use the server certificate instead.