Missing part of OpenVPN ovpn config?

I’ve installed the OpenVPN Rock-on, went through all the documented steps, but somehow my phone won’t connect through OpenVPN for Android. It hangs on the Authenticating step, and sure enough, on the Rockstor side, the logs show this:

okt 08 09:33:02 rockbox dockerd[2882]: Sun Oct  8 07:33:02 2017 192.168.2.254:60204 TLS: Initial packet from [AF_INET]192.168.2.254:60204, sid=eaef8b3e 31468d35
okt 08 09:33:02 rockbox dockerd[2882]: Sun Oct  8 07:33:02 2017 192.168.2.254:60204 VERIFY ERROR: depth=0, error=self signed certificate: CN=MY_CHOSEN_CN
okt 08 09:33:02 rockbox dockerd[2882]: Sun Oct  8 07:33:02 2017 192.168.2.254:60204 OpenSSL: error:140360B2:SSL routines:ACCEPT_SR_CERT:no certificate returned
okt 08 09:33:02 rockbox dockerd[2882]: Sun Oct  8 07:33:02 2017 192.168.2.254:60204 TLS_ERROR: BIO read tls_read_plaintext error
okt 08 09:33:02 rockbox dockerd[2882]: Sun Oct  8 07:33:02 2017 192.168.2.254:60204 TLS Error: TLS object -> incoming plaintext read error
okt 08 09:33:02 rockbox dockerd[2882]: Sun Oct  8 07:33:02 2017 192.168.2.254:60204 TLS Error: TLS handshake failed
okt 08 09:33:02 rockbox dockerd[2882]: Sun Oct  8 07:33:02 2017 192.168.2.254:60204 SIGUSR1[soft,tls-error] received, client-instance restarting

Attempting to connect from my laptop (Fedora 26, imported the .ovpn file into the NetworkManager) results in these log lines:

okt 08 09:43:00 rockbox dockerd[2882]: Sun Oct  8 07:43:00 2017 Authenticate/Decrypt packet error: packet HMAC authentication failed
okt 08 09:43:00 rockbox dockerd[2882]: Sun Oct  8 07:43:00 2017 TLS Error: incoming packet authentication failed from [AF_INET]192.168.2.254:49864

Did I miss anything specific for client setup?