Screeching noise

I am using Audacity 2.3.3 on Windows 10.

When I change pitch on a track and export it, I get a screeching sound on playback and cannot hear any music at all. Can anybody advise, please?

Which version of Audacity?

Does the track play correctly before you change the pitch?
Does the track play correctly after you change the pitch?
How much have you changed the pitch?
What format are you exporting as?