Try handling unclosed sql connections by calling dispose on the engine before it is put back into the pool.

cdplib/db_handlers/SQLHandler.py

@@ -26,7 +26,7 @@ class SQLHandlerPool(metaclass=SingletonThreadsafe):
     def __init__(self, size: int = 20):
         self._size = size
         self._log = Log(name='SQLHandlerPool')
-        self._log('############################# CREATED NEW POOL ###################################')
+        self._log.info('############################# CREATED NEW POOL ###################################')
         self._sql_handlers = [SQLHandler() for _ in range(size)]
 
     def aquire(self):