Listeners declared in plugin.xml not working

Hello,

I am trying to register some listeners using the <applicationListeners> tag in the plugin.xml as shown in https://jetbrains.org/intellij/sdk/docs/basics/plugin_structure/plugin_listeners.html 

They don't show up in any way, whether using println or breakpointing the listeners in the debugger.

I got this so far:

<applicationListeners>
    <listener class="com.github.chicoferreira.projecttimecounter.listener.HeartbeatEditorMouseListener"
              topic="com.intellij.openapi.editor.event.EditorMouseListener"/>
    <listener class="com.github.chicoferreira.projecttimecounter.listener.HeartbeatVisibleAreaListener"
              topic="com.intellij.openapi.editor.event.VisibleAreaListener"/>
</applicationListeners>

What I have in the plugin.xml inside <idea-plugin>

package com.github.chicoferreira.projecttimecounter.listener

import com.github.chicoferreira.projecttimecounter.HeartbeatService
import com.intellij.openapi.diagnostic.logger
import com.intellij.openapi.editor.event.EditorMouseEvent
import com.intellij.openapi.editor.event.EditorMouseListener
import com.intellij.openapi.fileEditor.FileDocumentManager
import com.intellij.openapi.project.Project

class HeartbeatEditorMouseListener : EditorMouseListener {

    override fun mousePressed(event: EditorMouseEvent) {
        val instance = FileDocumentManager.getInstance()
        val file = instance.getFile(event.editor.document)

        if (file != null) {
            HeartbeatService.registerHeartbeat(file)
        }
    }

}

package com.github.chicoferreira.projecttimecounter.listener

import com.github.chicoferreira.projecttimecounter.HeartbeatService
import com.intellij.openapi.editor.event.VisibleAreaEvent
import com.intellij.openapi.editor.event.VisibleAreaListener
import com.intellij.openapi.fileEditor.FileDocumentManager

class HeartbeatVisibleAreaListener : VisibleAreaListener {

    override fun visibleAreaChanged(event: VisibleAreaEvent) {
        val instance = FileDocumentManager.getInstance()
        val file = instance.getFile(event.editor.document)

        if (file != null) {
            HeartbeatService.registerHeartbeat(file)
        }
    }
}

I am using kotlin and intellij 2020.2 for this project.

I already tested this classes written in java, changing <applicationListeners> to <projectListeners> (+adding Project to constructor) and setting activeInTestMode=true in both listeners. Nothing works.

Am I doing something wrong?

Thank you.