Ionic serve doesn't reload on save (livereload)

This is my ionic info.

alxk (test *) aide $ ionic info

cli packages: (.../ProjectsIonic/aide/node_modules)

    @ionic/cli-plugin-cordova       : 1.6.1
    @ionic/cli-plugin-ionic-angular : 1.4.1
    @ionic/cli-utils                : 1.7.0
    ionic (Ionic CLI)               : 3.7.0

global packages:

    Cordova CLI : 7.0.1

local packages:

    @ionic/app-scripts : 2.1.3
    Cordova Platforms  : android 6.2.3
    Ionic Framework    : ionic-angular 3.6.0

System:

    Android SDK Tools : 26.0.2
    Node              : v8.2.1
    OS                : Linux 4.10
    npm               : 5.3.0

I just opened VSCode and type ionic serve, I got a message to update ionic to newest version:
I typed Yes. Same happened with cli-plugin-cordova and cli-plugin-ionic-angular. This was what ionic did:

npm install --save-dev --save-exact ionic@latest
npm install --save-dev --save-exact @ionic/cli-plugin-cordova@latest
npm install --save-dev --save-exact @ionic/cli-plugin-ionic-angular@latest

Then I served my project: ionic serve -l and livereloading stoped working.
I tried to change the livereload port:

ionic serve -l -r 35730

I tried to remove node_modules and install again:

rm -R node_modules/
npm install

I tried to remove node_modules and package-lock.json and install again:

rm -R node_modules/
rm package-lock.json
npm install --save

I tried to use an incognito chrome window.
I tried to delete cache browser.

I ran out of ideas.
Someone knows what is going on? How can I solve this problem? What else can I do?

What do you mean by that? Did it first work and then not? Did it never work with CLI 3.7? How are you testing if it works? What file are you changing how?

Yes, it worked with previous version, I think it was 3.6.1.

Not with this version.

I’m modifying files.

I’m modifying components, pages (templates, ts and scss) and providers. With anyone of them works.

EDIT:
When I modify content inside assets folder, it reload and output this at console:

[19:26:05]  copy update started ...
[19:26:05]  copy update finished in 295 ms

Isn’t ionic serve livereload by default?
Does it rebuild when running ionic serve when you change a file? Or no changes in the console at all?