... you lose anything above the default stack size when it hides the materials before using the portal.
ie: You approach the portal with a stack of 130 copper ore, the ore is hidden from the server so you can use the portal, upon arriving you're hidden stack is returned to you - at the default size of 30 (meaning you just lost 100 ore)
ArgusMagnus[Mod Author]
What are you using to increase stack sizes? Cllc?
GTLAN
Yes - it is CLLC
ArgusMagnus[Mod Author]
I've received similar reports with at least one other stack-modifying mod. I'll try to look into it, but can't promise anything (because I myself have only access to a vanilla client, so there's no way I can actually test this). For now you should consider SQoL incompatible with increased stack sizes in general (not just this mod, any SQoL mod)
GTLAN
That's fair - I appreciate what you're trying to do with these and love the idea of server only mods. My server uses a mix of both your mods and server/client mods as I'm locking down the potential for any exploiting, which server sided mods don't cater for (ie: characters all being saved to the server and reloaded when connecting).