PowerShell Script to iControlSnapIn Not Working

Recently i've also upgraded one of F5 node to version 14.1.2.3. And i've also gone through similar kind of issue which was related to script. While executing script, error observed was like could not initiate connection with supplied information. Post checking thoroughly, we found that script was configured to send request strictly with TLS1.1 and that request was failing. When we asked backend team to configure TLS1.2 in script, the script started working fine. Virtual Server where this request was hitting had configured TLS1.1 but still request was failing. But yes, making changes in the script solved issue. This issue seems to be kind of same issue that you're observing so shared here. I am not sure but this may help you to correlate issue.

Mayur