I changed ec2 instance type from t2 medium to c5 xlarge and i can t use it

Question

I changed an ec2 instance type from t2.medium to c5.xlarge When restarted success. I can't connect it in private network. I got the error:Failed to connect to the host via ssh: ssh: connect to host ip-xx.internal port 22: Connection refused

before that, all is well

ena driver is enabled. but ethtool -i eth0 got if

filename:       /lib/modules/4.9.0-7-amd64/kernel/drivers/net/ethernet/amazon/ena/ena.ko

version:        1.0.2

license:        GPL

description:    Elastic Network Adapter (ENA)

author:         Amazon.com, Inc. or its affiliates

srcversion:     73A3C8A8AA3F11D64B6D173

alias:          pci:v00001D0Fd0000EC21sv*sd*bc*sc*i*

alias:          pci:v00001D0Fd0000EC20sv*sd*bc*sc*i*

alias:          pci:v00001D0Fd00001EC2sv*sd*bc*sc*i*

alias:          pci:v00001D0Fd00000EC2sv*sd*bc*sc*i*

depends:

retpoline:      Y

intree:         Y

vermagic:       4.9.0-7-amd64 SMP mod_unload modversions

parm:           debug:Debug level (0=none,...,16=all) (int)


shell #sudo ethtool -i eth0

driver: vif

version:

firmware-version:

expansion-rom-version:

bus-info: vif-0

supports-statistics: yes

supports-test: no

supports-eeprom-access: no

supports-register-dump: no

supports-priv-flags: no