How are you resetting? How long are you holding the buttons? What do the LEDs do?

Hi @Racso 

Welcome to the Sonos Community!

Sorry to hear of the issue you are having with your Play:5 not resetting.

If you follow the steps on our Factory reset your Sonos product help page exactly and don’t get a flashing green light, 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. The most common mistake is to let go of the button before the light flashes orange. Note that it may help to wire the speaker to the router with an ethernet cable before resetting - if this does help, you won’t need to ever do it again with this particular speaker.

I hope this helps.