Using aws secure tunnel to access the device via ssh, running cat greengrass log froze the session

Established a secure tunnel to my greengrass core device. I can reach to the device without problem. I can list /greengrass/v2/logs, and then when I run cat greengrass.log, the session is frozen. Even with CTRL-C, I can not get out of that session. I could not run another ssh session as well. The localproxy is configured with default setting: { "tunneling": { "proxy": { "default_bind_address": "localhost", "message": { "data_length_size": "2", "data_frame_max_size": "65538", "max_payload_size": "64512", "max_size": "65536" }, "tcp": { "connection_retry_count": "5", "connection_retry_delay_ms": "1000", "read_buffer_size": "131076" }, "websocket": { "ping_period_ms": "5000", "retry_delay_ms": "2500", "connect_retry_count": "-1", "reconnect_on_data_error": "true", "subprotocol": "aws.iot.securetunneling-1.0", "max_frame_size": "131076", "write_buffer_size": "131076", "read_buffer_size": "131076" }, "region_endpoint_overrides": { "cn-north-1": "data.tunneling.iot.cn-north-1.amazonaws.com.cn", "cn-northwest-1": "data.tunneling.iot.cn-northwest-1.amazonaws.com.cn" } } } } I noticed that the response is slow from the device when I type before I ran cat. i understand there is a bandwidth limit for secure tunnel, but it should not freeze.