Blu-ray sharing failures with FCP 10.5 update

I archive old home videos to DVD and BD-R Discs using FCP. When ready, I share in four different formats (.mov, .m4v, .mp4, DVD, and Blu-ray). For DVD and Blu-ray, they are shared first to the desktop (ISO image created) and then burned to a disc. Everything still works like a champ with the FCP 10.5 update, except Blu-ray.

Since the update to FCP 10.5, Blu-ray share fails when it gets to 33% rendering. It doesn't matter if the video is one hour or one minute in length, it always fails at 33% with the following message:

Share failed. the share operation "Blu-ray: "22.264.264" has failed. Details: Error: H.264 encoding failed.

I've restarted FCP, restarted the computer, deleted Render files, used a different library, created a new project, used different clips, and used clips that I've burned successfully in the past. I always get the same fail message at 33% only when sharing to Blu-ray.

Any help is appreciated.