We will fix this bug in a new update which will be released soon.
Until then, if you need the delay feature, you can modify wp-content/themes/elvyre/js/jquery.nivo.slider.js.
Go to about line 642 and 643 and modify those values as you wish:
animSpeed: 500, pauseTime: 3000,
Those values will affect portfolio slider, I’ve tried changing them and it works.