Saw a variety of issues including: 1 of 4 players was endlessly falling stuck underground the middle of the farm.
After that, the joined players visually lacked all crafting recipes, but were still able to craft the previously unlocked ones, though the icons remained silhouetted.
Afterwards, player-to-player movement was very choppy, moving items for remote users did not correctly reflect server state (client-side duplicated & deleted items), and remote users failed to load in inventories when opening the UI.
Attached images show endless falling issue, the remote player missing inventory UI panel, and the missing (visual) crafts.
Saves & backup saves also zipped & attached.
#Severe Player Desync, Host Unaffected
idle trail
hushed prairie
Hello @idle trail,
Thank you for bringing this to our attention!
For the endless falling issue—could you check out the video another player shared here:
#1409771042745876480 message
Kindly see if it looks like what your partner’s experiencing. Thank you!
idle trail
No, when they fell off the map their view was locked to one position on the farm.
I've attached some images of that, as we tried to help them.
hushed prairie
No, when they fell off the map their view was locked to one position on the farm...
Thank you for your reply.
Just to double-check,
• The first pic (with the tree) is from the player who actually had the issue,
• and the second pic is from your POV where you see their name on the ground, right?
Also, do you remember the in-game date when it first happened? And your partner and your in-game activities before it occurs?
Every detail of the previous steps will be very helpful to help us narrow things down. Thanks again! 
idle trail
No, they're both from the affected PC's client. I'm the visible player, and neither of us are the host.
We're on Day 11, which should be the same day as the current save in the zipped files.
There were no prior issues on previous days, either.
As far as in-game activities, we explored some floors of the mine, placed several crafting tools, and were proceeding with basic skills.
hushed prairie
No, they're both from the affected PC's client. I'm the visible player, and neit...
Copy that! I'll relay this to the team for further review. We'll get back to you if the team has any questions or updates. Thank you so much! 
hushed prairie
Hello @idle trail,
Quick question—did the issue happen while the player's in-game ping was high (around 100–200ms)? 😮 Thanks a bunch!
idle trail
One player has consistent internet issues (~10% packet loss), but otherwise ping should be alright.