I purchased the MP3 Jukebox module from Velleman (Ref VM202N): https://www.velleman.eu/products/view/?id=417492

and I have some trouble making the connections on my breadboard. (I'm a newbie)

Here is what I think is the best I can do:

The result is that the music plays correctly (it is amplified quite too much by the power amp though, given my 8 Ohm/0.5W speakers), the LED is blinking together with input noise intensity, but the push buttons are not doing the appropriate thing:

1. None of the buttons connected to a resistance really work
2. The only push button connected without a resistance don't do the "previous song" action. Instead, it lowers the volume if I keep it pushed, and, when released, the volume goes back to max.

My only guess so far would be that I should use reversed buttons, but it doesn't work either if I tried to fake a reverse behavior (using my finger to hold the buttons down, and removing one of them to trigger a "click").

I don't want to rush into buying new buttons if the error is elsewhere.

PS: The values of the resistors are correct. I double-checked multiple times.

Here are some more pics: