I had a riddle in fletcher rest who ask to go form the south torch to a east ssouth east tree. But it's impossible to dig there. I saw some comments on reddit with the same bug.
@fintito first: Fetcher
Second: yes that's an unfortunate bug. I already got the same riddle it's impossible to dig around that tree
HitokiriShaggy
Ship Mate
I ran across this same bug. Was trying to get it for 30 minutes and with all the other c**p going on (volcanoes and gysers) we gave up and went and sunk some ships.