iZotope plug-ins use complex DSP, which can create audible latency. During playback, this can result in a delay or offset to a single track's output, which can put a track out of sync with the rest of a mix.
Most modern audio applications include latency compensation and can automatically compensate for this offset, however, if you are noticing latency when working with iZotope plug-ins in your host, here are a few things to try:
Make sure the "Enable delay compensation"* feature is enabled in the Options/Preferences window. This option is available in the General section under "Latency" or "Delay Compensation."*Note that this feature reports the exact offset in samples to the host application. The host itself will need to compensate for the offset.
Make your host's delay compensation feature is enabled. This will usually be available in the preferences window or an options/settings menu.
If your host application does not support Delay Compensation, you can still manually adjust your track to compensate for the offset. The current offset is available in the "Latency" or "Delay Compensation" section of the Options/Preferences panel.