Not having seen your setup I would say that it may be an internet issue, we have had a few reports of very slow internet outside the major towns and cities and that obviously affects Kinderloop 'talking' to the servers.
Its a good idea to run the internet speedtest at https://speedof.me/
this will tell you what speed your internet is coming in at, if its lower than 4MBps then thats pretty slow. Its a good thing to test throughout the day as well to see if there is a pattern in slowness as the internet signal does fluctuate depending on how many people are using it in your area!
Also, if you have slow internet, your wifi strength could be strong but its still pushing a slow internet connection so perhaps test in the different rooms )