When you are marketing your place as premium. Make sure your place is clean, safe and mold free. Also use furniture and equipment and items in the house including linens and toiletries as premium. you used the most cheap lamps and linens from IKEA. You provided barely any shampoo and condition for 4 days of stay. Your place smelled like mold (in the first apartment). Your apartment was designed cold and bare with no personal touch. Your appliances were out of order. Your elevator was not working. Your windows and doors were in bad repair condition. Also it was hot in the apartment without AC. The cooler were just name sake and did not do anything to the temp. In that case we had to keep the doors open but because there was no screen. There were mosquitoes and bugs constantly coming in to the apartment. Extremely cheap and uncomfortable bedding and pillows.
The apartment if furnished better and managed with how the good airbnb's are managed could produce a good outcome. Stop being so greedy for rent and late checkin money that you forget the actual quality and hospitality.