Multiplayer desync issues

[Steam][1.0.38.0.29][Synchronization] Multiplayer game-breaking desync issues

Summary
While starting new world in coop after a while we got unplayable desync issues mainly on client side. We are playing in crossplay mode - host is on Steam(me) and client is on Epic(he).

After some time(usually around hour or half an hour) connected client starts to experience lot of issues - client drops an item from inventory on a ground or stores it in container it stays in his inventory. When I as a host pick that item I can use it until client switch back to that specific item that stayed in his inventory and it will instantly go to his hands and my hand is bugged/glitched until I switch to another item that I have.

Another issue is when client starts to drop items in quick succession - then it will start doing some weird stuff - items on ground disappearing randomly going to his inventory back or being lost completly. It can also happen with buildings and crafting. For example - if client builds a building/crafts an item I as a host can not see it. If it is building he can see it but usually can not use it. In case it is shelter for example he can not use it (menu for sleep/save does not pop up). In case it is anchor he can not drop it. I as a host can not see it. I can for example see client standing in air and on his side he see himself on standing on a shelter. If client destroys this desync building no building materials are dropped and it just removes building. If it is crafted item and he drops it and I take it it is in most cases lost. It just dissapears.

Another set of issues can happen with materials/rafts and other movable stuff or enemy mobs - client can see those things on different places than host. Pigs killing me but I can see a pig standing on other side of island. Raft is displaced and he sees me standing on water. This stuff usually sync itself after I as a host interact with it. Move it with right mouse button/use it etc.

Seed
#52054965

Settings
No custom island added. Graphics settings set to ultra with motion blur turned off. Resolution 2560x1440. Camera smoothing set to 0.

Steps
Playing for some time - usually not that long half an hour/hour.

Extras
-Have you tried reloading your save, game or PC?
Restarting game usually repair desynced items/buildings by showing client what I as a host sees. Built stuff that I am not able to see is lost then it starts doing weird stuff after some time again. We both reloaded PC and router. We also tried multiple new saves on other slots and it always happend again.

-Have tried reinstalling the game?
Yes we both reinstalled game and tried to play on new save - it happened again. Also I have game on Epic games store and we tried to play both on Epic - it happend again.

-Is there anything else you tried to alleviate the issue? Please let us know whether it was successful or not.
We have tried VPN and mobile internet connection just in case to be sure that our providers are not poor quality or blocking something. We have also tried other regions to host a game and switch client/host role. Everyhing stayed same - after some time it gets desynced. Strange is that on Europe region we got ping around 110ms on RU region we have 100ms other regions are higher. Our location is Czechia for both of us. I have been trying to play game with different friend on Epic games year and half ago on different version (sadly I can not remember version number) and it was SAME! Only difference was that my other friend had a poor ADSL connection and we assumed it is causing it. My connection was different provider than now but it was stable 1Gbps optic (FTTH). Now - year and a half later - we are both playing on stable optic connection 1Gbps without visible issues in other multiplayer games. And it stays basicaly same. I can see same issues as before.

Next session we also want to try this: https://www.reddit.com/r/strandeddeep/comments/uewcsp/multiplayer_sync_bug_easy_fix/
But I am not expecting much of it based on nature of issues. Also because it just sync after restarting game(loosing resources/buildings but is synced)

I will attach a basic speed test result from my side to this post.

Feel free to let me know if you need anything else I can tape a video of issues next time we got time to play together or provide you with more tech spec if you want to. Just let me know what would help you. But I would rather play than work because we got a little time to play together these days… I would like to help solve this issue because it is sad for me to see such a nice chill game being unplayable for us.

Sorry for typos it is just too late at night. I hope this is understandable since english is not my first language.

I am looking forward to your reply.

1 Like