iphone 6 passcode

My iPhone 6s started to not recognise Wifi connection at home after an update about one month ago. No WiFi for a few minutes, then it would appear. Now, I had been using my Iphone all day on and off - picked it up and instead of unlocking with a fingerprint recognition as always it asked for my passcode. I put the passcode in and it said not recognised. I am using the correct passcode.

Tried to speak to Apple but they want the IMEI number before they will start a conversation - and that's in the phone that I cannot access.

Seems that this is a bug in the OS, there are numerous complaints on various forums of the same issue. Does Apple want me to buy a new phone? or am I just very unlucky like many others.

iPhone 6s has been a good phone and I consider it up to myself when I upgrade phones, at the moment I am happy with a dated Iphone, it does what I need it to do but now I have to change it.

Anyone any views?