Charlie,
Thank you very much for your time, as well as for the tips and feedback you shared with us.
I wanted to let you know that we have successfully resolved the issue. After further investigation, we discovered that Windows Defender (Windows 11 Enterprise) was blocking requests from ColdFusion API Manager 2018 to port 8500. Once we configured the appropriate inbound rule in Windows Defender, communication was restored and the issue was fully resolved.
By the way, I noticed that in your third point you mentioned ColdFusion API Manager 2023 and 2021. Could you please let me know where these versions can be downloaded? We have tried to upgrade our API Manager 2018 installation using the update feature available in the API Manager Administrator, but it always reports that no updates are available.
Thanks again for your support and assistance.
Best regards,
Israel C.