1. A one-sentence summary of bug:

It didn't take the diamonds from my inventory after left-clicking the item to be purchased in the chest. 

2. Priority to fix? 

High

3. Which server?

Spawn

4. Steps to Reproduce: Please list the step-by-step methods to reproduce the issue

(1) Searched for the shop that sold slimeballs - /shopsearch item SLIME_BALL.

(2) Tp'ed to the topmost shop which was Proz3n's - /$ Proz3n.

(3) Went to the chest which sold 64 slimeballs for 1 diamond.

(4) Opened the chest and left-clicked a stack.

5. Expected Outcome: What did you expect to happen?

That the stack of slimeballs would go to my inventory and a diamond would be taken from my inventory and be moved to the space where I took the stack. 

6. Actual Outcome: What happened instead?

The stack stuck to my cursor and I waited for a while for 1 diamond to be taken from my inventory. When that didn't happen, I wanted to put the stack back but it wouldn't let me. I put the stack in my inventory and tried putting instead one diamond in the chest and that didn't let me as well. I tried doing it once more by taking another stack of slimeballs and I see if it took my diamonds but it didn't. Therefore, I essentially took two stacks of slimeballs for free. 

7. Proposed Fix (Optional): Do you have a suggestion?

8. Notes (Optional): Anything else we should keep in mind in relation to this issue?

I'm currently trying to reach out to the shop owner cause I ain't taking free stuff. 

9. Screenshots (Preferred): Do you have screenshots of the problem, proof or reference?