Worst Travel-Experience I had in 20 years (and I have been to 43 countries)!
Communication with the host was difficult from the very beginning.
There was a scaffolding standing in front of the bedroom window where people were climbing up and down, a complete flat renovation/gutting just opposite on the 2nd floor. Neither was mentioned to me before.
Even though the host offered to refund me for the extreme noises and scaffolding, he didn’t do it till today.

I found a dirty bathroom with a mouldy shower, a mouldy showerhead (fan was not working, no window), dirty bedsheets, dirty cups, dirty cutlery, no coffee machine (even though shown on the pictures). There was a Nespresso machine but not a single capsule.
A curtain rod fell on my head, when I tried to close the curtains in the bedroom. Stains on the curtains.
The host admitted that the pictures on AirBnB are 5 years old and that the apartment needs maintenance.
The front door is squeaking extremely, so if I was not woken by people standing in front of my bedroom window or the workers in the construction site, it was this enormous noise from the front door.
Communication deteriorated after I wrote him about the obvious maintenance and cleaning problems.
Obviously, my mistake was that I complained to the host first and gave him a chance to fix things. He pretended to, but things did not improve.
I was hit by the curtain rod again next morning and his advice was: Do not open curtains and bedroom-windows (which is absurd, because I want to open windows in a flat).
Most window seals were not in order.
After using the stove, a fuse turned off, so something is not in order there too.
I had to ask for the wifi, how the TV would work (it didn’t). I had to ask for a second key, I had to ask for the right door code. All those things are normally prepared by the host for a guest who is new in the apartment.
And usually there are at least one or two coffee capsules for the first morning or enough toilet paper to last for a day.
When things did not improve on my first day in the flat, I wrote to AirBnB. Till today the so-called customer-service refuses to help me, because I moved in on October 4th, even though I had reserved (and paid) the apartment from October 3rd on.
I gave the host a chance to fix things on October 5th. He didn’t.
Instead he wrote me on WhatsApp “Stop ruining my life”.
I had to block him.
My learnings:
Never give the host a chance to fix things or contact you on WhatsApp.
Instead immediately complain to AirBnB – even though they will not help you.
For this much too high amount of money (1.707 Euros!!) I paid for 14 nights, I could have stayed in a very nice hotel where I would have had a certain standard of cleanliness and comfort, professional communication and a real customer service.