PIONNER AVH-X7800BT Bluetooth Connection Issue: Connected Without Phone, Restore Settings

Hello 
I bought a PIONNER AVH-X7800BT car radio a few days ago and, since yesterday, I’ve been having trouble connecting via Bluetooth.
To be honest, at the very beginning I paired my phone with the radio as normal and Bluetooth was working, but when I tried to reconnect my phone to the radio via Bluetooth, it connects but displays ‘Connected without phone’ and still nothing works.
I’ve tried to remove the paired devices, but I can’t do so because the Bluetooth function isn’t highlighted – it’s as if the radio doesn’t have that function at all. I also wanted to try restoring the factory settings via ‘RESTORE SETTINGS’, but this option isn’t highlighted either and I can’t access it.
Has anyone else come across a similar situation, or do you know of any other way to reset this radio? HELP

Disconnecting from the power supply does not reset the settings?

I tried by disconnecting the cubes and then the same, I was supposed to try to disconnect the battery but I don't know if it would help at all .. I thought there was maybe some other way to restart.

See if you have a hole in the OPEN button, there is a reset button inside, you need to press it with a straightened paperclip or similar tool.

Ok radio, I restarted the phone connected to Bluetooth, but still without a phone and I do not have a phone book, in addition, I am sending a picture where the BT icon is still not lit and I cannot enter it

Maybe the problem is in the phone settings - check on the phone if there is an available player in the car on the BT list and if the permissions are not blocked there.

I checked but I'm afraid I can't check it

Added after 11 [minutes]:

Honestly, I looked through the whole phone but I can't find anything like that ...

What kind of phone is it?

Huawei p10 - when I enter BT there are no settings. I downloaded the appradio application, but it is for ISO 7.0 and I have Android 7.0. I thought that somehow I could connect it with a cable and try the program, but nothing too.

>>16683069 There’s a green cable at the back of the radio; you need to earth it to something.

In your phone’s Bluetooth settings, next to the name of your radio, there should be a star icon, an ‘i’ or an arrow; you need to tap it and grant permissions. It’s an old phone – I used to have it, but I can’t quite remember the details. On the system I’m using now, you can select various devices: headphones, a speaker, a car audio system, or a hearing aid. There’s also an option for ‘Multimedia and Contacts’ only.
Weronika, please go through the Bluetooth settings again carefully – you must have missed something in your haste and determination 😉

Archived topic – there has been no discussion here for 9 years. Please only reply if you have some advice to offer.