Help using flanger in Ocenaudio

I’ve just begun to use Ocenaudio and I’m trying to apply effects such as flanger. I’m not sure why but no matter what I do the effects are not working. I click apply after making adjustments to the delay (or any) settings, and the audio bar visually seems to change, suggesting to me that the effects I have added should be part of the audio track, but then when I play it, the audio sounds like I haven’t added anything. Perhaps I’m missing something stupid and simple but if any one knows I would really appreciate some help! Thank you!