Synchronize via Timecode now not working

Hello,

I record video via a BlackMagic HyperDeck, and audio via a SoundDevices MixPre10-II. I have the HyperDeck set as the Timecode source, with a BNC cable run to the MixPre, and the MixPre reads the timecode from its BNC input. I take the files straight into Premiere, place them on a timeline, select them, right click, Synchronize, Timecode. This method has worked for months, but recently has stopped working. When I click on Synchronize, the Timecode option is completely greyed out. I can however, merge clips using Timecode. I just can’t synchronize them on the timeline. Here’s some details:

• HyperDeck MP4 files with QuickTime TC track flagged as stripped
  • This includes all files that have worked previously but now don’t
• MixPre-10 II BWF audio at 30fps non-drop
• Timecode option greyed out in Synchronize dialog across multiple Premiere versions including 25.6.5 and 26.2
• Media preferences set correctly with Timecode: Use Media Source
• Merge Clips with timecode works, Synchronize does not
• Old files from February that previously synced now also fail

Attached is the MediaInfo text for my audio and video files.