Greetings from Syncfusion.
To proceed further on the reported issue, please share us the following details.
1. Whether our extensions installed and Syncfusion menu alone not appear in Visual Studio 2019?
2. Follow the steps suggested in the below KB article link and send us the zip file which consists of complete Syncfusion Installer logs generated by our tool. http://www.syncfusion.com/kb/2331
3. Visual Studio 2019 About Window screenshot.