I found out that cobblestone slabs and cobblestone are both worth 1. I wasn't sure if this was a bug where you can get 2 from every 1 cobble or on purpose. So I'm reporting it because you can get 2 from one cobble and I think it might be a bug.
This issue has been added to our JIRA and will be looked at within 24 hours. An update will be posted to the thread when fixed by @JamieSinn
This looks to be a duplicate of https://www.ecocitycraft.com/forum/threads/skyblock-exp-discrepancy.175536/ You can track your bug here: https://jira.ecocitycraft.com/browse/ECCDEV-75 @LeosZombie @Mission001