Issue with a fixed phone Essentiel B Dect/Nivalis

Thank you
Yes, my phone is connected to a box.
I will do it immediately and I will keep you posted

Among the icons present in the image below, which ones are displayed on your device's screen?

Please specify if any of them are blinking
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It is very difficult to catch a black cat in a dark room.
Especially when it isn't there...

When I open the call log, it says unavailable.
I bought this phone on June 14, 2019, it's still under warranty;
Yes, with no results, whereas this morning, the person picked up, could hear me but I couldn't hear them. It was my sister who told me this when she called my mobile. And as luck would have it, I live above a village where the reception on my mobile is unpredictable, sometimes it works, other times it doesn't, hence the importance of my landline... especially right now!
Yes, in my opinion, the volume is set correctly. The ringtone volume works well.

I reconnected my box... still no improvement...
Do you agree that we continue the investigations tomorrow or is there nothing more to be done?
In any case, thank you for your solidarity and persistence.

I turned off the power to my box for about 10 minutes, and the problem is still not resolved. I still don’t have a dial tone. I’m going through my user manual to see if I made a mistake during setup...(I’ve already done the mute trick!)....I can’t find anything.
I reset my phone, and that didn’t work either.

The icons present, from left to right and from top to bottom:
signal icon, with power-saving mode enabled (E); zero-emission mode activated;
the missed call icon and that one is flashing (it's the only one)
the battery icon (the battery is full)
the date, the time
the answering machine activated

There you go. A big thank you, I reply late but I did some tidying up so as not to stress too much with a landline that no longer works.

Thank you very much Baladur 13 for not letting me down!
I deleted the Eco and Eco Plus modes and the icons no longer display, as well as the Zero Emission Mode icon.
I activated Voice Frequency but for now there is no change and the Missed Call icon is still blinking.

Try resetting the default settings
See notice page 36/37
and once again... unplug the power supply of the box for a minute

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It's very difficult to catch a black cat in a dark room.
Especially when it's not there...

I just reset it and I will turn off my box for a minute, then I will come back to the forum to give you the result.
Thank you very much, as always.

Wonderful! It's working again! I don't understand what happened...
But a big thank you for your help, I felt supported and understood and I believe it is thanks to you that it is functioning again.
I am grateful to you.
Take care of yourself and your loved ones during these difficult times.
Best regards.

Today everything is fine, I feel reassured.
You are a valuable person and thank you for your patience.