Why does my iPhone Classic not connect to wifi anymore?

A couple of months ago my iPhone Classic started only connecting sometimes to wifi & it continuously lost connection. A few weeks ago, in addition to no more automatic connects, it also quit accepting requests to search for a certain wifi router. I get the message "Could not scan for wireless networks." However, the spinning circle of lines beside the "Choose a Network..." still spins. This means that not only am I stuck with supper excessively slow data connects for e-mail, Maps, etc. but it is also not available to use routers while traveling for more precise positioning in Maps. My iPhone is not tampered with & is up to date.

ThankU,

DarrellSY