xtang2010

Have same problem, found somehow the disconnect order is important. Ie: async with ClientSessionGroup() as group: session1 = await group.connect_to_server(server_params_list["filesystem"]) session2 = await group.connect_to_server(server_params_list["excel"]) await group.disconnect_from_server(session2) await group.disconnect_from_server(session1) This works...

Some further debug showed this related to how BaseSession is using anyio.create_task_group(). I don't think it has anything to do with ClientSessionGroup, thus I created [issue#922](https://github.com/modelcontextprotocol/python-sdk/issues/922)