Hi @Jeff Hays ,
Does this issue persist all the time?
Do you have any operations before this issue happened?
In my experience, voice policy is a factor that can make you receive the same caller ID. You can try to check it by running the command “Get-CsVoicePolicy”. For more details:
https://learn.microsoft.com/en-us/powershell/module/skype/get-csvoicepolicy?view=skype-ps
In addition, we recommend you try to use the snooper to analyze the conversation you want to troubleshoot. For more details about snooper description, you can learn it from:
https://commsverse.blog/2017/03/07/skype-for-business-snooper-and-sip-deep-dive-refresher/
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