HDMI sound popping and crackling

Hello, I just bought a new Mac mini 2018 and connected it to my monitor (Asus MX34VQ) with an HDMI cable.

My issue is that my monitor keeps producing short static sound issue, like popping and crackling. I get 1 or 2 pops every 10 seconds, and it is quite annoying.

The things I have tried so far (to no avail):

- Resetting PRAM and SNC several times.

- Changing the HDMI cable and using a new one: same result.

- Changing the HDMI port on the monitor (it has 3 HDMI ports): same result.

- Starting in Safe Mode (but Safe Mode supports no sound output, so it was useless - obviously with no sound output I got no static sound issues).

- Creating a new partition, fresh install of 10.14.1, but the sound issue is there too (even in the language selection screen).

- Connecting a different monitor to the Mac mini, with a different HDMI cable. This way there are no static sounds, but the audio is somehow distorted (especially at high volumes) and the video colors seem completely distorted too (e.g. white turns to yellow).

- Connecting my Mac Book Pro to the Asus monitor: no sound issues with that configuration.

- Checking if the monitor has any firmware update or driver for Mac, but it has neither.

- Adjusting the settings in Audio Midi Setup, according to some comments on forums that suggested to lower the Khz. I was at 24-bit, 48 Khz and turned it to 16-bit, 32 Khz (the lowest setting my monitor provides), but nothing changed.

If I use my headsets or the Mac mini internal speakers, I get no static sound whatsoever.

Before I take the Mac mini to an Apple Store, I'd like to know if anybody else has experienced the same issue, and how they solved it in case.

Thanks a lot for your suggestions and help.