@Christopher Poluyi
Thank you for your post!
Based off our Microsoft Defender for Cloud Apps - Microsoft Sentinel integration documentation, I wasn't able to find any information on this, but I don't see why there would be an issue with connecting additional apps after integrating with Sentinel. However, since your question of connecting additional apps to Cloud Apps after integrating with Sentinel, is more related to Microsoft Defender for Cloud Apps, I'd recommend reaching out to their experts via the Microsoft Defender for Cloud Apps Tech Community.
If you aren't getting an answer to your question, I'd also recommend following the Microsoft Defender for Cloud Apps Support and troubleshooting documentation.
Create an online support request for Defender for Cloud Apps
Additional resources
If you have any other questions, please let me know.
Thank you for your time and patience throughout this issue.
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