Workigng with MXF footage from new Sony camera, combination of 4.2.2 and 4.2.0, rec.709 and sLog 3. Playback started flickering on all clips. On current public release it plays fine.
Sorry for the issue. Can you please share the device information and screenrecording of the issue? Please share some of these media files and project file, if possible. I would like to test it on my local system and take this up with my team. https://helpx.adobe.com/creative-cloud/help/share.html