Give threads less time to shut down gracefully. Attempt shutdown() rather than stop() on the telnet connections to see if that improves things

providers/spot/rbn.py

@@ -1,5 +1,6 @@
 import logging
 import re
+import socket
 from datetime import datetime
 from threading import Event, Lock, Thread
 
@@ -41,9 +42,13 @@ class RBN(SpotProvider):
         self._stop_event.set()
         with self._telnet_lock:
             if self._telnet:
+                try:
+                    self._telnet.sock.shutdown(socket.SHUT_RDWR)
+                except (AttributeError, OSError):
+                    pass
                 self._telnet.close()
         if self._thread:
-            self._thread.join(timeout=15)
+            self._thread.join(timeout=5)
             if self._thread.is_alive():
                 logger.warning(f"RBN (port {self._port!s}) worker thread did not exit on time and will be killed.")