I am having a new issue that is not going away. I am editing an hour long documentary sequence, multi-cam 4k in a 1080p timeline. For the last three days I am getting the spinning beach ball for about 1 to 2 seconds and then an another second delay every time I tap the space bar (push play). I have restarted the machine three times, closed and reopened final cut, checked the speed of the server, etc. No issues anywhere that I can find. Everything is optimized and the problem is consistent whether I am playing back full quality or better performance; scopes and angles open or closed. I am editing on 2013 Mac Pro with dual d700 fx card. (this graphics card was warranted 6 months ago after a failure) plenty of ram. Editing off of an XSAN with fiber channel. No lag in speed on the XSAN.
Once it begins playback, it does fine. But stopping and then restarting it is a consistent lag with beach ball before it starts again.
No new plugins, at least not any that have been applied to this timeline. We did update final cut library manager, but that is it really. I have rendered the timeline with the same issue. I'll try the direct connect method and build a small local library to see if the problem is the same. Good idea!
4 Years later and I am looking at your thread. I have discovered quite by accident that at least in my case it is something to do with the roles. If I turn off the dialog roles in the timeline index options the problem goes away. Anyone reading this - I hope that give a clue.