Are those of you with issues accessing it remotely?
Maybe that's why it works for me. I'm doing it locally.
Accessing remotely. Edge seems to be behaving now for me. 
Local only here. Live tv worked this morning on newer prerelease ( thanks @tmm1 ! )
I’ll try some recorded stuff later on.
I spoke too soon, I'm getting buffering to the point of being unwatchable...1-2 seconds of video followed by 10+ seconds of buffering. Plenty of bandwidth on both ends so that's not the issue (Plex streaming working perfectly). Also tried several different transcoder and quality settings with no change. Logs show this:
2022/03/16 20:10:30.294528 [ENC] Starting encoder for The Witchfinder S01E02 2022-03-15-2159.mpg in /shares/DVR/Streaming/file19126-5dc63dd5d12e-57013086/encoder-58-932109921 at 58 (91.700011) (encoder=libx264, resolution=720, deinterlacer=linear, bitrate=2744, segment_size=0.01)
2022/03/16 20:10:30.323838 [HLS] ffmpeg: file19126-5dc63dd5d12e: [h264 @ 0x6373740] mmco: unref short failure
2022/03/16 20:10:30.356750 [HLS] ffmpeg: file19126-5dc63dd5d12e: [mpegts @ 0x634abc0] start time for stream 2 is not set in estimate_timings_from_pts
2022/03/16 20:10:30.356931 [HLS] ffmpeg: file19126-5dc63dd5d12e: [mpegts @ 0x634abc0] Dropped corrupted packet (stream = 4)
2022/03/16 20:10:30.356935 [HLS] ffmpeg: file19126-5dc63dd5d12e: [mpegts @ 0x634abc0] Dropped corrupted packet (stream = 1)
2022/03/16 20:10:30.360212 [HLS] ffmpeg: file19126-5dc63dd5d12e: [mpegts @ 0x634abc0] Dropped corrupted packet (stream = 4)
2022/03/16 20:10:30.360217 [HLS] ffmpeg: file19126-5dc63dd5d12e: [mpegts @ 0x634abc0] Dropped corrupted packet (stream = 1)
2022/03/16 20:10:30.373656 [HLS] ffmpeg: file19126-5dc63dd5d12e: [h264 @ 0x6406e80] mmco: unref short failure
2022/03/16 20:10:33.365530 [HLS] ffmpeg: file19126-5dc63dd5d12e: /shares/DVR/TV/The Witchfinder/The Witchfinder S01E02 2022-03-15-2159.mpg: corrupt decoded frame in stream 0
Same issues here.
For no reason whatsoever, I changed the DVR URL to HTTP-only (i.e., changed it from "https://192.168.1.x" to "http://...") and it started working fine.
- Firefox running on iOS
- DVR 2022.03.14.2329 running on a Synology DS1621+