Hi @Romulorochabr
Welcome to the Sonos Community!
I’m sorry to hear of this issue you are having with not getting any TV sound from your Beam. It sounds most frustrating!
Please try unplugging the TV from the power and disconnecting the Fire Stick. Plug the power for the TV back in - do you then get TV audio successfully? If so, then it appears there is a HDMI-CEC conflict causing the issue. With the link now made, you might then be able to plug in the Fire Stick (it does not need the ARC port - any HDMI port will do, though it may still need a higher-specification HDMI port than others, if available) and still get audio. If not, you may need to purchase a cheap CEC blocker to fit to the Fire Stick to resolve the issue.
If none of that works, however, I recommend you get in touch with our technical support team who have tools at their disposal that will allow them to give you advice specific to your Sonos system and what it reports.
I hope this helps.