Upon arrival, all was fine. Getting the keys is easy, the apartment looks like on the pictures even though the kitchen would benefit from a bit more equipment (e.g. 4 glasses, plates, etc for 4 guests). The keys didn't work properly, but the problem was resolved within a short time frame. The Wifi had some issues (not available everywhere in the apartment) but we were offered access to a second network which did the job. Had that been it, I would have given 4 stars.
However, on day 2 of our planned 9 day stay we woke up to a sewage spill from one of the bathrooms which had flooded parts of the hall and bedroom too, and that's when things went downhill. We called Propr and they sent a staff member to take a look who left with no resolution. We were then asked to wait for the plumbers to arrive (which meant we had to change our Saturday plans - ok...). The plumbers started to do their "magic" and half an hour later the bathroom, bedroom, hall, and kitchen / lounge were covered in 2-3cm of sewage. At that point we insisted to be moved and Propr (after initial hesitation) sent over alternative options, so we moved our stuff that night.
I won't go into much detail, but I felt the situation was handled poorly with little acknowledgement how bad our experience was. Plumbing issues can happen, that's unlucky, but after seeing the floors covered in multiple centimeters of sewage for 12+ hours, I was unpleasantly surprised to find that the apartment was offered to guests on Airbnb less than 5 days after the incident. This makes me wonder about the hygiene standards as sewage can present a serious health hazard and if that was my place, I would have replaced the floors in the affected rooms.