Apple TV cannot find wi fi on new tv.

[HappydaysArehere]

Would be so pleased if anyone can help me. Had a Sony Bravia 40w705cbu new TV delivered. It was set up easily with our virginmedia wi fi. No had trouble ever before connecting to my iPad and MacBook Pro. Have now added an Apple TV via hdmi port. It showed the apple icon but said it couldn't locate my wi fi and said I should check in settings. I did and everything is connected. There is another offer in settings to join the TV's network. I tried this but it requires the tv's password. I tried the passwords used to set up the wi fi on the tv but no luck. We had used this Apple TV on another tv but due to a shortage of hdmi ports causing us to use a double adapter it often didn't connect. However, when setting up originally it immediately connected to my iPad and my Apple ID. Now there is no such connection. I also noticed of late that my iPad no longer shows air play but appears to be replaced by air drop. I am wondering if this is the problem! If anyone could help I would be so grateful.