My Apple Pay - which goes via my Wi-Fi when I am at home - stopped working recently; it would try to process a payment but then repeatedly said the process had failed, but did not tell me why.
I suspected a problem with my card or the bank, but eventually I discovered that there were outstanding Apple security updates on my phone and my computer. They are set to automatic update, but I switch both completely off every night, so they probably never get the chance.
I updated both devices and Apple Pay then worked perfectly again. Nice to know that with out of date security, Apple Pay will not work - makes it a little safer.
Might be a similar issue with you, although all the phones in the house simultaneously ? Has one of your offspring been fiddling with the Wi-Fi hub settings perhaps ?
If not, have you updated your Wi-Fi hub ? - there might be a security update outstanding. Must check mine.