MacBook Pro keeps waking up from sleep

Wake reason: RTC (Alarm)

Indicates either a wake for network access or a scheduled power event.

Wake reason: EC.LidOpen (User)

If you didn't open the lid at that time, the lid sensor is faulty.

"Wake reason: EC.LidOpen (User)" is the time at which I close the lid... is that normal?

No, you would normally see that when you open the lid, not when you close it.

Please test after taking each of the following steps that you haven’t already tried:

Step 1

Take all the applicable steps suggested in this support article, including the ones under the heading "If the previous steps don't work." That's the starting point for any further effort to solve the problem.

Note that, as stated in the article, the computer will not sleep if some sharing services are enabled. From the menu bar, select

 ▹ System Preferences... ▹ Sharing

Turn off all sharing services.

Also note that the "external devices" referred to in the article could include Bluetooth devices, other than those made by Apple. If you're using a MacBook, MacBook Air, or MacBook Pro, or if you're using a desktop Mac with a wired keyboard and mouse, turn Bluetooth off to test.

Step 2

If iTunes Music Sharing or Home Sharing is enabled, disable it or quit iTunes. Do the same with any third-party applications that have a similar feature.

Step 3

Select

 ▹ System Preferences... ▹ Accessibility ▹ Speakable Items: Off

Step 4

Select

 ▹ System Preferences... ▹ Bluetooth ▹ Advanced...

and uncheck both boxes marked

Open Bluetooth Setup Assistant at startup if...

Step 5

Reset the printing system.

Step 6

Back up all data.

Triple-click the line below on this page to select it, then copy the text to the Clipboard by pressing the key combination command-C:

/var/vm

In the Finder, select

Go ▹ Go to Folder...

from the menu bar and paste into the box that opens by pressing command-V. You may not see what you pasted because a line break is included. Press return.

A folder named "vm" should open. Inside it, there may be a file named "sleepimage". Move that file, and only that one, to the Trash, but don't empty yet. You'll be prompted for your password. Close the folder window.

Restart the computer and empty the Trash.

I also did some additional steps like changing my anti-virus from Avast to Avira

You could have gone one better and just have no antivirus software on your Mac at all. You just switched from one bad horse to another. Just type in Avast or Avira in the search box at the top of any forum page to get an idea of how useful or useless these are.

How Power Nap works on your Mac - Apple Support

Please remove "Avira" by following the instructions on this page. If you have a different version of the product, the procedure may be different.

Back up all data before making any changes. Never install any "anti-virus" or "anti-malware" product again.

Have you confirmed that it doesn't wake up while in safe mode?