Hello! What version are you using? Broadcast workflow was refactored in 7.6.04 and also in 8.

Do you hav the screen shot of where in SRM it's visible...basically public stuffs should only be visible there as srm is meant for end user...

I have this exact same issue and am on ITSM 7.6.04 Patch 4.  Also, when I attempt to workflow correct this the SRS:Broadcasts form has an error indicating a field mismatch on the table with CFG:Broadcasts.  There is obviously something missing in this workflow.

this is the workflow Active Link:SRS:SRC:Broadcast-Set_z1DViewInternalBroadcast which allows the logged in user to view the internal broadcast...basically...if the person logged in is the support staff then only this active link should do pass and perform set field action

so as of now may be you can try to disable it and flush midtier and browser cache and test how it goes...and if this is making the difference..then after you can have one active link before to this which would go to people form and check the logged in user profile has support staff yes or not...if yes then set some field and then let this active link:SRS:SRC:Broadcast-Set_z1DViewInternalBroadcast fire after this one and checking that varaible if only logged in user is support staff then allow him to view the internal broadcasts...