Sequencer Frames Render Black When Four or Less Frames Are Rendered

Occurs: 5/5 times

**MRQ renders black frames when custom playback range is set to four frames or less.

Regression does not occur: tested using //UE4/Release-4.27 @ CL 18429761 GH

Note: Issue does not occur in Windows. Appears to only occur on Linux.

Repro Steps:

1. Create FPS Template project.
2. Enable MRQ plugin.
3. In MRQ leave Deferred Rendering with default settings.
4. In Output, enable custom playback range.
5. Set Start Frame to 0 and End Frame to 3 or less, and accept.
6. Render local.

Expected: Render frames reflect the level viewport camera view.
Actual: Select frames are black.