On my fire stick and other Plex TV clients, I can hit the arrow button and play will fast forward 10-30 seconds depending on brand. On my LG-webos, it doesn’t do anything. I have this on multiple LG TV’s so I know it’s not local to just 1 TV.
When I hit the arrow button to move forward, I can see the highlighted part of the bar that pops up. I know it’s trying to move forward but when I release the button, it goes right back to where it was which makes it impossible to fast forward. It used to work fine about a year or so ago. I’ve dealt with this for quite a long time and finally decided to investigate more.