north willow
TL:DR
Remove Krypton and if that's not enough remove Chipped
Longer explanation
fabric has a networking problem at large scales, with the amount of data it can handle when working with server or when opening to LAN which is why you get that error in multiplayer but not singleplayer, don't quite know why removing Krypton helps since that's supposed to help with networking.... but if removing Krypron is not enough and you plan to add a few custom mods, then removing Chipped is the best way i have found to make it work as Chipped adds a TON of blocks and recipes which is just a ton of data to process, so removing that open up a "headroom" of sorts for just working or adding a few mods that does not add a ton of things
After removing those mods i have been able to add AE2Things and Storage drawers and Connected glass, and i can still join my world on server
spice moth