Can not connect to VNC session from local network

few days ago we updated Debian from old stable to stable (Linux 6.0.0-0.deb11.6-amd64). While updating, machine reboot had to be done, which ended some important processes, such as vncserver, which we used for connecting from local and also remote network (local connection using vncviewer, remotely from PuTTY - Win machines or other utilities - MacOS, specifically I don't know). After restart, I tried to start all virtual desktops manually using vncserver : and server started as expected. This command provided output below: 3NI3X0 New Xtigervnc server ': ()' on port for display :. 3NI3X0 Use xtigervncviewer -SecurityTypes VncAuth -passwd /home//.vnc/passwd : to connect to the VNC server. But we are no more able to connect to virtual VNC desktop using f.e. vncviewer (we do not have xtigervnc SW installed, we used vncviewer and it has always worked). I'm using vncviewer : command to connect. After confirming command error window pops up saying: 'The connection was refused by computer'. I also managed to find vncviewer.log with additional info, please see below: VNC(R) Viewer 6.21.406 (r44671) x86 (Apr 7 2021 10:26:47) Copyright (C) 2002-2020 RealVNC Ltd. RealVNC and VNC are trademarks of RealVNC Ltd and are protected by trademark registrations and/or pending trademark applications in the European Union, United States of America and other jurisdictions. Protected by UK patent 2481870; US patent 8760366; EU patent 2652951. See https://www.realvnc.com for information on VNC. For third party acknowledgements see: https://www.realvnc.com/docs/6/foss.html OS: Debian GNU/Linux 11, Linux 6.0.0, amd64 2023-02-09T10:11:22.902Z vncviewer[]: CModuleHosted: Getting CloudConfig.pkg from built-in resource 2023-02-09T10:11:22.904Z emperor vncviewer[]: VendorConfig: Error in Certificate "CN=GeoTrust Global CA,O=GeoTrust Inc.,C=US": X.509 Error: Certificate expired 2023-02-09T10:11:22.904Z vncviewer[]: VendorConfig: Error in Certificate "CN=GlobalSign,O=GlobalSign,OU=GlobalSign Root CA - R2": X.509 Error: Certificate expired 2023-02-09T10:11:22.910Z vncviewer[]: CModuleHosted: Using business identifier 2023-02-09T10:11:22.940Z vncviewer[]: CModuleCtrlComms: Listening on /tmp/.vnc-/vncviewer.CtrlComms. 2023-02-09T10:11:22.943Z vncviewer[]: GoogleAnalytics: X.509 Error: Certificate expired 2023-02-09T10:11:22.953Z vncviewer[]: CSession: Connecting to : (Chooser for Direct UDP/Direct TCP via proxy settings) 2023-02-09T10:11:22.956Z vncviewer[]: CSession: connection error: connect: Connection refused (111) 2023-02-09T10:11:22.956Z vncviewer[]: CConnection: close: [System-111] The connection was refused by the computer Surprisingly, while connecting from remote network (i.e. non-local), virtual desktop works just fine. Same with SSH connection - it is able to connect to using ssh command, but we also need GUI for some tasks. I did not find any relevant informations on how to solve this issue and in our team we really need it for work purposes. Do you think, that we need some kind of new autentification keys to be able to connect from local network? I will be more than happy, if you could give me some relevant informations, which could lead to solving this issue. Have a nice day.