So, weird issue. ZLevels is the only mod affecting Chainsaw/Jackhammer on my server and the issue has gone away since I disabled the chainsaw/jackhammer being effected by ZLevels. What will happen is you'll be hitting a tree with a chainsaw or using the jackhammer on a node and they just break. You sloooooowly get the correct amount, but it's the amount per hit so you just lost out on a lot of resources. Hoping we can get this fixed. 

The plugin does by default excludeboth tools from being recognized by the plugin:

    "excludeChainsawOnGather": true,
    "excludeJackhammerOnGather": true,​

ZLevels is the only mod affecting Chainsaw/Jackhammer on my server and the issue has gone away