On my LG c1 while seeking any DV 7 FEL video black screen appear for a second, DV profile 8.1 profile work fine though. I tried stable, nightly, cpm a9, cpm a10, nothing helped. Is this some tv model specific problem?
Try it with player-led turned on in the settings, also use the latest beta PM4K 0.8.0-beta5.1. What happens after a second? C1 should work with FEL just like the C2 and C3. I assumed you have tried multiple movies and or have a known good device to test them on?
I tried player-led, also I tried watching using pm4k 0.7.9-rev and PM4K 0.8.0-beta5.1 and also directly from SMB server and emmc of ugoos, problem reoccurred in any environment. I am using FEL test file from this post and multiple DV movies. After black screen playing continues normally, no DV logo appears or smth like that. Sometimes black screen remains for longer time, but I cant replicate it reliably.