Cant reach to internet when start a docker container

Docker Desktop
1
  1. I ssh logined to the NAS, and can ping reach to “www.docker.com”, =Internet，through a router.
  2. I start any docker container using docker start xxx, ssh session works well, but i cant ping reach to the Internet on the ssh session.
  3. I stopped the docker container by docker stop xxx, I can ping reach to the Internet on the ssh session.
  4. I tried iptables-save, and iptables-restore, none effect the problem.
2

Docker Desktop and NAS, can you provide more context? What command is run on which device?