Hi @wendycollins4 ,
Welcome to Trend Micro Home Users Community!
Apologies for the inconveniences this has caused you. If screen mirroring isn't working after removing Trend Micro, it means Trend Micro isn't causing the issue. It would be advisable to seek assistance from Apple Support for further troubleshooting.
Alternatively, you can follow Apple's recommended steps to resolve this issue by clicking on this link.
Hope this helps.