Problems Rendering Song To Disk

Theres a song I’ve recently finished and sounds pretty good played back in Renoise. However, when I export it, somehow one of the synths plays something completely different and in another key than what I originally sequenced. When i go back into the renoise file, it plays normally but whenever its exported to wav it plays back differently. I can post the xrns file and the mp3 if no one knows the solution to it(not sure if its a common problem). Thanks in advance.

Did you rendered in VST compatability mode?
If not, try if that resolves your problem.

If not:
Did you rendered it in a higher frequency than usual? (e.g. 48Khz).
If so, does rendering in 44Khz resolves the problem?
Some VST instruments cannot follow a different frequency rate than 44Khz or expect the host to be set to it.