Recording Issues

I have recorded a simple song (happy birthday sung through the desktop mike) on Windows 10 Audacity version 2.3.2. On playback the song fades in and out. I have never had this problem before. It doesn’t happen on simple voice recording on Windows 10. Please help. It may be the new version of Audacity that is giving me a problem? I attach the file recording for info. Thanks
Recording Issue.aup (1.15 KB)

Make sure [u]Windows Enhancements[/u] are turned OFF.

I have turned off the Windows enhancements as instructed :>) I have also checked that the Realtek HD drivers are up to date. I have also restarted the desktop. Unfortunately this doesn’t seem to have worked. Any other suggestions? Thanks