Kiwi.com complaint: Second flight lost

On the 30th April 2022, I bought a flight ticket priced $980 on the kiwi.com website from Dushanbe (Tajikistan) to Porto (Portugal) via Istanbul (Turkey). As the flights were with two different airlines, I made sure there was enough layover time (2h40, please see proof attached). The first flight in Dushanbe was delayed, leaving me with 1h layover. Kiwi had emailed me the day before stating I would not be able to check in for.the second flight online. When I got to Istanbul, I had to wait in a massive queue to have my passport check, exit and get to the check-in counter. When I got there, check-in had closed. I was advised to go to customer services, where I was informed boarding was completed and therefore I was not allowed to check-in anymore. I lost the second flight, which meant I spent 50€ in a room for the night, aside from the 460€ I had to spend on a flight to Porto for the next day. Kiwi customer service states I have no right to any compensation as they believe I had enough time between flights. That is not accurate – it would have been true had I been able to check-in online in advance for the second flight.