Live TV has no option to view "live" from mobile apps

This has been bugging me for months so I’m not sure what started it. When I tune to my live TV programming via the Plex app on either my iPhone or Android tablet, it starts the broadcast either from the beginning of the airing or some random point that is not live/current. There is no option to skip to live and dragging the timeline slider over to the right usually ends up in a black screen and an error. It never successfully switches to the live view. Watching live TV via a computer browser is fine, as is watching live TV directly via the HDHomerun app on my iPhone. Can anyone please help me figure this out? It used to work flawlessly and I’ve kept my Plex server (running on a Synology DS920+) up to date. I’ve even completely removed my HDHomerun tuner from Plex and readded it.

Server Version#: 1.42.2.10156-720010156
Player Version#: current iOS & Android Plex apps (no updates available)
Tuner Make/Model: HDHomerun Flex Quatro HDFX-4US
Guide/Lineup name:
Using XMLTV?:
Channel number/Name: any live OTA channel
<If providing server logs please do NOT turn on verbose logging, only debug logging should be enabled>