KDE6 OpenVPN Plugin connection failed

Hello,
after updating to KDE6 the KDE OpenVPN Modul doesn’t connect.
KDE6 OpenVPN Plugin connection failed

journalctl   -b | grep vpn                                                                                  ✔ 
Mai 14 21:10:40 user NetworkManager[479]: <info>  [1715713840.2865] vpn[0x55fb732c93e0,ed70a5ef-e8b5-4e64-9401-09e1a16bd197,"ovpn"]: starting openvpn
Mai 14 21:10:40 user nm-openvpn[1363]: DEPRECATED OPTION: --cipher set to 'AES-256-CBC' but missing in --data-ciphers (AES-256-GCM:AES-128-GCM:CHACHA20-POLY1305). OpenVPN ignores --cipher for cipher negotiations.
Mai 14 21:10:40 user nm-openvpn[1363]: OpenVPN 2.6.10 [git:makepkg/ba0f62fb950c56a0+] x86_64-pc-linux-gnu [SSL (OpenSSL)] [LZO] [LZ4] [EPOLL] [PKCS11] [MH/PKTINFO] [AEAD] [DCO] built on Mar 20 2024
Mai 14 21:10:40 user nm-openvpn[1363]: library versions: OpenSSL 3.3.0 9 Apr 2024, LZO 2.10
Mai 14 21:10:40 user nm-openvpn[1363]: DCO version: N/A
Mai 14 21:10:40 user nm-openvpn[1363]: WARNING: No server certificate verification method has been enabled.  See http://openvpn.net/howto.html#mitm for more info.
Mai 14 21:10:40 user nm-openvpn[1363]: NOTE: the current --script-security setting may allow this configuration to call user-defined scripts
Mai 14 21:10:40 user nm-openvpn[1363]: TCP/UDP: Preserving recently used remote address: [AF_INET]X.X.X.X:443
Mai 14 21:10:40 user nm-openvpn[1363]: UDPv4 link local: (not bound)
Mai 14 21:10:40 user nm-openvpn[1363]: UDPv4 link remote: [AF_INET]X.X.X.X:443
Mai 14 21:10:40 user nm-openvpn[1363]: NOTE: UID/GID downgrade will be delayed because of --client, --pull, or --up-delay
Mai 14 21:10:40 user nm-openvpn[1363]: [Fireware SSLVPN Server] Peer Connection Initiated with [AF_INET]X.X.X.X:443
Mai 14 21:10:46 user nm-openvpn[1363]: OPTIONS ERROR: failed to negotiate cipher with server.  Add the server's cipher ('AES-256-CBC') to --data-ciphers (currently 'AES-256-GCM:AES-128-GCM:CHACHA20-POLY1305') if you want to connect to this server.
Mai 14 21:10:46 user nm-openvpn[1363]: ERROR: Failed to apply push options
Mai 14 21:10:46 user nm-openvpn[1363]: Failed to open tun/tap interface
Mai 14 21:10:46 user nm-openvpn[1363]: SIGUSR1[soft,process-push-msg-failed] received, process restarting
Mai 14 21:10:47 user nm-openvpn[1363]: WARNING: No server certificate verification method has been enabled.  See http://openvpn.net/howto.html#mitm for more info.
Mai 14 21:10:47 user nm-openvpn[1363]: NOTE: the current --script-security setting may allow this configuration to call user-defined scripts
Mai 14 21:10:47 user nm-openvpn[1363]: TCP/UDP: Preserving recently used remote address: [AF_INET]X.X.X.X:443
Mai 14 21:10:47 user nm-openvpn[1363]: UDPv4 link local: (not bound)
Mai 14 21:10:47 user nm-openvpn[1363]: UDPv4 link remote: [AF_INET]X.X.X.X:443
Mai 14 21:10:48 user nm-openvpn[1363]: [Fireware SSLVPN Server] Peer Connection Initiated with [AF_INET]X.X.X.X:443
Mai 14 21:10:54 user nm-openvpn[1363]: OPTIONS ERROR: failed to negotiate cipher with server.  Add the server's cipher ('AES-256-CBC') to --data-ciphers (currently 'AES-256-GCM:AES-128-GCM:CHACHA20-POLY1305') if you want to connect to this server.
Mai 14 21:10:54 user nm-openvpn[1363]: ERROR: Failed to apply push options
Mai 14 21:10:54 user nm-openvpn[1363]: Failed to open tun/tap interface

Does anyone else have problems with OpenVPN after upgrading?

I’m not familiar with openvpn or perhaps the GUI you use to configure it.
But the error messages seem to tell what to look for/adapt:

Mai 14 21:10:40 user nm-openvpn[1363]: DEPRECATED OPTION: --cipher set to 'AES-256-CBC' but missing in --data-ciphers (AES-256-GCM:AES-128-GCM:CHACHA20-POLY1305). OpenVPN ignores --cipher for cipher negotiations.
...
Mai 14 21:10:46 user nm-openvpn[1363]: OPTIONS ERROR: failed to negotiate cipher with server.  Add the server's cipher ('AES-256-CBC') to --data-ciphers (currently 'AES-256-GCM:AES-128-GCM:CHACHA20-POLY1305') if you want to connect to this server.
...
Mai 14 21:10:54 user nm-openvpn[1363]: OPTIONS ERROR: failed to negotiate cipher with server.  Add the server's cipher ('AES-256-CBC') to --data-ciphers (currently 'AES-256-GCM:AES-128-GCM:CHACHA20-POLY1305') if you want to connect to this server.
Mai 14 21:10:54 user nm-openvpn[1363]: ERROR: Failed to apply push options

You need to use an AUR package for that?

Mai 14 21:10:40 user nm-openvpn[1363]: OpenVPN 2.6.10 [git:makepkg/ba0f62fb950c56a0+] x86_64-pc-linux-gnu [SSL (OpenSSL)] [LZO] [LZ4] [EPOLL] [PKCS11] [MH/PKTINFO] [AEAD] [DCO] built on Mar 20 2024

Have a look here, your issue might be related: OpenVPN profiles no longer work in NetworkManager after 20240513 update - #7 by jonnyabu

Yes, it looks like the same problem. As a workaround I also edit the OpenVPN Config files in /etc/NetworkManager/system-connections