Fix issue with stop if queued

ui.py

@@ -274,7 +274,7 @@ def build_interface() -> gr.Blocks:
         # 3. Training & Eval Tab
         
         # 3a. Training
-        run_btn.click(
+        train_run_event = run_btn.click(
             fn=lambda: (
                 gr.update(visible=False), 
                 gr.update(interactive=False), # Lock Reload
@@ -283,7 +283,8 @@ def build_interface() -> gr.Blocks:
                 gr.update(visible=True)       # Show Stop
             ),
             outputs=[run_btn, reload_btn, eval_btn, zip_btn, stop_btn]
-        ).then(
+        )
+        train_run_event = train_run_event.then(
             fn=UIController.run_training,
             inputs=[engine_state, *train_ui["params"]],
             outputs=train_ui["outputs"],
@@ -303,7 +304,7 @@ def build_interface() -> gr.Blocks:
         )
 
         # 3b. Evaluation
-        eval_btn.click(
+        eval_run_event = eval_btn.click(
             fn=lambda: (
                 gr.update(interactive=False), # Lock Run
                 gr.update(interactive=False), # Lock Reload
@@ -311,7 +312,8 @@ def build_interface() -> gr.Blocks:
                 gr.update(visible=True)       # Show Stop
             ),
             outputs=[run_btn, reload_btn, eval_btn, stop_btn]
-        ).then(
+        )
+        eval_run_event = eval_run_event.then(
             fn=UIController.run_evaluation,
             inputs=[engine_state, *train_ui["eval_params"]],
             outputs=[train_ui["outputs"][0]] # Output only to log, not plot
@@ -325,7 +327,11 @@ def build_interface() -> gr.Blocks:
             outputs=[run_btn, reload_btn, eval_btn, stop_btn]
         )
 
-        stop_btn.click(fn=UIController.stop_process, inputs=[engine_state])
+        stop_btn.click(
+            fn=UIController.stop_process,
+            inputs=[engine_state],
+            cancels=[train_run_event, eval_run_event]
+        )
 
         reload_btn.click(lock_ui, outputs=action_buttons + [push_btn, zip_btn]).then(
             fn=UIController.handle_reset,