diff --git a/ingestor/managers/ingestor_manager.py b/ingestor/managers/ingestor_manager.py
index 78b442f..382bc94 100644
--- a/ingestor/managers/ingestor_manager.py
+++ b/ingestor/managers/ingestor_manager.py
@@ -105,7 +105,8 @@ class IngestorManager():
         """
 
         registered_servers = []
-        for _slot, slot_config in self.managed_tags.items():
+        current_managed_tags = self.managed_tags.copy()
+        for _slot, slot_config in current_managed_tags.items():
             for server, server_config in slot_config.items():
                 registered_servers.append(server)
                 server_config = server_config.copy()
@@ -137,7 +138,7 @@ class IngestorManager():
                         f"removing server from managed tags."
                     )
                     _a = [self.managed_tags[slot].pop(server, None)
-                          for slot, _value in self.managed_tags.items()]
+                          for slot, _value in current_managed_tags.items()]
 
         for server in list(self.opc_managers.keys()):
             if server not in registered_servers: