Troubleshooting CCU3 Web Interface Access Issues

Hello everyone, I’ve recently acquired the Homematic IP heating control system along with the CCU3 base station. Everything seems to be working perfectly on the Homematic app, but I’m having trouble accessing the CCU3 web interface through my browser. I’ve tried multiple browsers like Firefox, Chrome, IE, and Edge, but none of them can connect using the IP address or the URL http://ccu3-webui/. The error message I receive is ‘Server not found.’

I’ve already disabled the firewall and rebooted my router, but the issue persists. My setup includes a Telekom Speedport Smart router, a Windows 10 Pro notebook, and ESET antivirus. I’m hoping someone in the community might have encountered a similar issue and could offer some advice. Any help would be greatly appreciated! Thanks in advance.