Iphone XS won't connect to home wifi

Dear all, yesterday I felt my internet speed was slow so I switched off wifi and used my data. This morning it won't connect to wifi. I chose network and it asked for password, which is a set password from Sky and cannot be changed. It says password is wrong. My iPad Pro and iMac are connected to wifi fine. I first did a full hard start. No luck. I forgot network and tried but still does not accept password. I reset network settings, but still nothing. Can you help please