I'll try to explain as best as possible:
-When switching between online/offline mode, my equipped armor and weapons as well as items in backpack don't carry over. As well as mutations I have unlocked from when online. I've found that if I place everything in a storage chest before saving/leaving that everything will be there in the chest when I switch back to either online or offline though.
-Water droplets fall through the ground by the south east marsh between the marsh and wolf spiders.
-Even though equipped, sometimes dandelion tufts won't open. Noticed that they disappear from the bottom right, have to remove and re-equip them to show up on screen and use. (In multiplayer too)
-Weevils and aphids are stuck under the rocks around the pond to the right of the oak tree.
---MULTIPLAYER---
-If there's 3 of us playing for a bit (haven't really timed it, sorry) and a 4th tries to join a while later it tells them to enter password even though there isn't one, or it just won't let them join. Host saves and quits, starts new lobby and all 4 of us can then play.
-In the same marsh/wolf spider area as single player, no one can see water droplets on grass. As host I could see them and as soon as I hit the grass and the droplets fell the others could see them on the ground.
-Wolf spiders are like 10x the normal size once in awhile, but only 1 person will see it that way.. *shudders*
-For everyone but the host, the oak tree looks like it's being engulfed by purple fire.