Some people have reported that certain types of LED's will screw up their connection. See what lights are turned on in the building and then turn them off and on and see if there is an effect on your connection. Maybe start with your own apartment and see if any lights or other appliances are affecting your connection too.
Anyhow, good luck---also check if the connection changes when street lights turn on too. At least you can narrow down where the problem can be then.
Anyhow, good luck---also check if the connection changes when street lights turn on too. At least you can narrow down where the problem can be then.