Plex DVR HDHomerun Extend not transcoding anymore to .MKV only .TS

I’m using Plex DVR to record to my HDHomerun Extend. Several months ago, the Plex DVR use to transcode directly to .MKV now only .TS. How do I get this feature back to have Plex DVR produce a .MKV file while recording?

I think this stopped in July 2017.

https://forums.plex.tv/discussion/comment/1476678/#Comment_1476678

(DVR) Use MPEGTS for all DVR recordings

I think you’ll have to post process the files to get a .mkv container.

EDIT: Another thread talking about it.