Hi @DDESIMONE thank you for your post here on the Zoom Community! It may be helpful to read through the options for Breakout Rooms in this support article. Perhaps you can pinpoint an area that caused the issue during the process
https://support.zoom.us/hc/en-us/articles/206476313-Managing-Breakout-Rooms
One helpful tip, if you are scheduling your meeting and Pre-Assigning people to BO Rooms, this will only work if the people joining the meeting are signed into the Zoom client with the same email address they used to register for the meeting. If people do not sign into the Zoom client, Zoom can't identify them, and if they aren't signed into the client with their same email, Zoom can't match the person to the registration.
Depending on your experience it may be simpler to automatically assign rooms once the meeting begins. But pre-assigning also works well as long as people are registering and signing in with the same email address.
If this has answered your question to your satisfaction, please click the "Accept as Solution" button below but if not please reply and we can continue the discussion. Thank you!