After I installed Oreo my notifications volume went very low - about 25% of the ringing volume. I was unable to find a way to change it though the settings. Third party applications are not working also - I tried Volume Control and Quick Volume Control but the notifications volume is still very low. 

Any ideas?

It's easy is an option in adjusting sounds right now I upload the steps

Thanks for your feedback conker!

ConkerVCL wrote:

https://ibb.co/etcKUT
https://ibb.co/bwZNio
https://ibb.co/jjfHG8

Thank you for the information, but this just raises the overall sound level of the phone, which in my case is now working - the phone ringtone level is too high and the notifications sound is still much lower.  There is no way to make them equal, or to control the notifications sound level separately. 
There are some third party applications that control this (Volume Control, Quick Volume Control, etc.), but they are not working with this ROM. Maybe there could be a control like this:

1) try with different notification sounds.
2) can you send a video when you try to raise the volume of the notifications from settings and quick bar if possible?

AleP wrote:

1) try with different notification sounds.
2) can you send a video when you try to raise the volume of the notifications from settings and quick bar if possible?

It worked. I changed the default notification sound a few times and no the volume level matched the ringing volume.
Thanks a lot!

prascho wrote:

AleP wrote:

1) try with different notification sounds.
2) can you send a video when you try to raise the volume of the notifications from settings and quick bar if possible?

It worked. I changed the default notification sound a few times and no the volume level matched the ringing volume.
Thanks a lot!

Not at all!
Have a good day!
Admin, so this problem is solved?

Yeah, problem solved