RDM failing to connect on some network interfaces

i've ran RDM via cmdline, and looks theres at least DNS issue. But it seems I'm not getting DNS servers provided by this unofficial VPN client.
Doesnt explain why my IP based RDP also fails or why other apps work. i'm looking into this more to get more accurate info...

DNS problem was a one-off yesterday. some laptop problem by the look of it which was fixed after a restart.

the RDM issue still persists though. can connect to vpn and use KRDC and Remmina without problem with DNS, but via RDM then i'm seeing DNS resolution issues.

$ flatpak run com.devolutions.remotedesktopmanager
[08:59:13:439] [2:00000021] [INFO][Devolutions.Rdp.Credentials] - [Parse]: parsing "a*******", "c*******.a*.u*" (Mstsc) => "Username: "a*******" Domain: "c*******.a*.u*""
[08:59:13:441] [2:00000021] [ERROR][com.freerdp.channels.virtual.channel] - [virtchan_virtual_channel_init_event_ex]: Unhandled event type 0
[08:59:13:442] [2:00000021] [ERROR][com.freerdp.channels.virtual.channel] - [virtchan_virtual_channel_init_event_ex]: Unhandled event type 0
[08:59:13:442] [2:00000021] [ERROR][com.freerdp.channels.virtual.channel] - [virtchan_virtual_channel_init_event_ex]: Unhandled event type 0
[08:59:13:447] [2:00000021] [INFO][com.freerdp.codec] - [openh264_load_functionpointers]: loaded libopenh264.so.7 2.5.1
[08:59:13:462] [2:00000021] [INFO][com.freerdp.codec] - [openh264_load_functionpointers]: loaded libopenh264.so.7 2.5.1
[08:59:13:464] [2:00000021] [WARN][com.freerdp.core.rdp] - [log_build_warn][0x7dd2a400fa00]: *************************************************
[08:59:13:464] [2:00000021] [WARN][com.freerdp.core.rdp] - [log_build_warn][0x7dd2a400fa00]: This build is using [runtime-check] build options:
[08:59:13:464] [2:00000021] [WARN][com.freerdp.core.rdp] - [log_build_warn][0x7dd2a400fa00]: * 'WITH_VERBOSE_WINPR_ASSERT=ON'
[08:59:13:464] [2:00000021] [WARN][com.freerdp.core.rdp] - [log_build_warn][0x7dd2a400fa00]: 
[08:59:13:464] [2:00000021] [WARN][com.freerdp.core.rdp] - [log_build_warn][0x7dd2a400fa00]: [runtime-check] build options might slow down the application
[08:59:13:464] [2:00000021] [WARN][com.freerdp.core.rdp] - [log_build_warn][0x7dd2a400fa00]: *************************************************
[08:59:13:464] [2:00000021] [WARN][com.freerdp.core.rdp] - [log_build_warn_cipher][0x7dd2a400fa00]: *************************************************
[08:59:13:464] [2:00000021] [WARN][com.freerdp.core.rdp] - [log_build_warn_cipher][0x7dd2a400fa00]: [SSL] {Cipher} build or configuration missing:
[08:59:13:464] [2:00000021] [WARN][com.freerdp.core.rdp] - [log_build_warn_cipher][0x7dd2a400fa00]: * des-ede3-cbc: RDP security FIPS mode will not work
[08:59:13:464] [2:00000021] [WARN][com.freerdp.core.rdp] - [log_build_warn_cipher][0x7dd2a400fa00]: *************************************************
[08:59:13:464] [2:00000021] [WARN][com.freerdp.core.nego] - [nego_enable_aad]: This build does not support AAD security, disabling.
[08:59:13:468] [2:00000021] [ERROR][com.freerdp.core] - [freerdp_tcp_resolve_host]: getaddrinfo failed with -2
[08:59:13:468] [2:00000021] [ERROR][com.freerdp.core] - [freerdp_tcp_is_hostname_resolvable]: ERRCONNECT_DNS_NAME_NOT_FOUND [0x00020005]
[08:59:13:471] [2:00000021] [ERROR][com.freerdp.core] - [freerdp_tcp_resolve_host]: getaddrinfo failed with -2
[08:59:13:471] [2:00000021] [ERROR][com.freerdp.core.nego] - [nego_connect]: Failed to connect

i do not seem to be seeing the same issue with the RDM deb version though - seems to connect fine, however i've had issues with that in the past so used the flatpak till now.

Hello,

This behavior is most likely related to the Flatpak sandbox rather than the VPN tunnel itself.

Flatpak applications operate within a sandboxed network and DNS environment. If the VPN provides DNS dynamically (e.g., via systemd-resolved or per-interface DNS), those settings may not be accessible inside the Flatpak sandbox. This can lead to hostname resolution failures in RDM, consistent with the "getaddrinfo failed" errors observed in the logs.

A suggested workaround is to use the native `.deb` version of RDM instead.

To clarify, this is not an issue with the VPN tunnel itself, but rather a known limitation of Flatpak when used with certain VPN DNS configurations. As a support technician, I’m unable to determine whether this is something that can be resolved at the application level.

That said, I will reach out to the development team and ask them to review your case.

Best regards,

I agree with your analysis/response.

`resolvectl` doesnt show any interface specific DNS config for the VPN interface, however the system is using systemd-resolved. Connectivity to the VPN then changes the nameservers listed in /etc/resolv.conf.

I'll continue using the deb version, but i was experiencing some issues with that in the past. Hopefully that issue has been fixed with general OS/RDM updates.

I did take a look at the flatpak RDM options using flatseal but nothing glaringly obvious that would improve this.

I'm working with the deb RDM though, so see how that goes and deal with things as they come...

Hello,

I discussed the issue with the developer, and it appears we’re aligned in thinking that Flatpak is the root cause. Unfortunately, there’s nothing we can do on our side to resolve it.

Best regards,