Node version reset when computer reboots

I installed Node 9.11.1 using nvm install and my projects can use the updated features but whenever I reboot I get reset to v6.10.1. I've checked this answer nvm keeps "forgetting" node in new terminal session and upon typing nvm list I see that the green arrow points to v6.10.1 but v9.11.1 is installed.

What do I need to do to make Node default to 9.11.1 after a reboot?

How do I change the default NVM?

Setting a default NVM version To set the default NVM version, you first have to make sure that version is installed in NVM. We can then run the following command to set this as our default version. You can check which versions you have installed by running the following command.

To set default version type: