Just purchased a WeatherTech 3-fold bed cover for my 2020 F-150 short bed. It was a lot cheaper than the Ford OEM cover. Doesn't open from the front though. I'll be pulling a 21C so can't comment on 5th wheel.
I left a request on the fold a cover site asking when they may be starting back up. I received a text from someone who has done business with them and he said they are done. Sad because it seemed like the best solution. Back to looking.