I have the '!' notif with a 10 like all item have finished to dry but when I pick a random one, the 9 others suddenly are not ready anymore
#Wrong notification on the Dehydrator
calm heron
calm heron
no answer ?
fading field
no answer ?
It's the weekend, and they only work regular office hours. However, there's been a few other reports about this issue, so they are probably already working on fixing it! 
https://discord.com/channels/623097219628662784/1407821948813054053
For now, either avoid putting new forage in late at night or if you do put in some, just leave it be for a few hours in the morning for the machine to finish. I think someone said it takes 10 hours to fully process.
bitter mortar
I've been having this same issue! I've put them in at different times and that doesn't seem to help either. It's happened at least 4 days of gameplay in a row. I might just hold off until it's fixed becuase it is a little frustrating :/