Hi ,
Other users were able to resolve it by uninstalling/reinstalling the Epic Games Launcher and Twinmotion then their Antivirus prompted them to allow Twinmotion to have access to the right permissions.
I recommend you follow the same steps and/or check to make sure your antivirus/firewall is not blocking Twinmotion.
Hope this helps and looking forward to hearing back from you.
Cheers,
Francesco