There are some days that will be a hit and others not so much. 

“Not so much” in my case means that I’m receiving just garbage that should not even reach my headphones. 
But the other moods looks not affected, so I get relevant suggestions there.
Just the flow looks affected.
They answered me that they’ll look at the issue.
I just hope that they can fix the issue, because paying for something that cannot fully be used it’s really annoying.
Also add that the suggested songs in the flow are exactly the opposite of my tastes, so “music” that I’d NEVER EVER wanted to listen to.

Flow works fine to me. It took some time for it to learn my tastes, but now I'm quite satisfied.
I would suggest you check out your favorite artists, albums and tracks, as well as blocked artists and tracks.
If everything is okay, then try to keep adding the artists, albums and tracks you like to your favorites, blocking the artists and tracks you dislike, and changing mood after selecting the unhappy emoji, so Flow may improve…
This article may help: Exclude An Artist Or Track From Deezer Recommendations.

I’m a Deezer user of Family since 2021 and of single user Deezer since a couple of years before.
I was also very satisfied by the “My Flow” suggestions, but now it is terrible!
Today it was impossible to use, while the “mood” suggestions are fine.
No idea what happened, but in so many years he should have learned my tastes.
And it started a couple of weeks ago with bad suggestions, but now it went crazy.
That’s why I opened this thread, to understand if I’m the only one experiencing such degradation or if there are more.

UPDATE

Today is Monday. The My Flow is back to its normal behaviour and it is suggesting related songs.
I’ve added no new songs on Friday, so nothing changed on my side, but now I have a normal flow.
This prove that there was something wrong in the suggestion algorithm. I hope that they discovered what and fixed forever.

It happened again! 
After a couple of weeks of normal behaviour, the flow is still showing tons of unrelated songs!
This looks happening always on Mondays. So I have to assume that the algorithm updates the flow behaviour on Mondays.
This means that for one week I cannot use flow!
I don’t know if some songs from my son’s account (that used to listen to sh*tty “music”) leaked to mine. If this is the case, it is a HUGE bug, because the only reason why I have a family account is to have separate accounts between us.
Please fix it. I’m again thinking to change to another music stream provider.

There is any way to see the FULL history of listened songs from my account?

As far as I know, it is limited to the last 100 songs. If you want your full listening history, you should ask Deezer Support.
When submitting the request, I would choose the values "My Deezer account" then "Request a copy of personal data" from the drop-down menus.
However, you should also contact the Help Center to have them check your account and explain why Flow behavior has been so strange to you lately.

Thank you for your answer.
The help center was already contacted in the past and got no satisfaction.
For some reason the next Monday the flow was again normal. It lasted a few weeks and now it is back to VERY bad suggestions.
At this point I already made my decision, after 6 years, to switch to a competitor and even saving a few euros per month. I cannot deal with a Company that doesn’t admit that there is something wrong in their algorithms and that cannot fix them. Also there is no Linux client and the community ones are not so good as Deezer’s competitors.
Next month I’m not going to renew the subscription and test something new.
I’m a bit sad, because it means to not sustain smaller companies and follow the main stream, which means less competition in the streaming music sector, but I cannot fight alone. I’m done with them. 

It’s sounds sad and I think it is understandable. If Flow and other recommandations don’t work anymore, there is no other option.

I agree that Flow inconsistently captures a listener’s tastes especially if they listen to different genres of music .