You may try moving the radio to an open location, possibly even
somewhat elevated off the ground. It may not be able to "hear" the
time frequency it is listening for, possibly due to interference or a
signal that just isn't getting to the unit. I have several clocks
located in a basement that set themselves from the WWV time signal,
and each time the batteries go dead, I actually have to put them
outside so they can listen in and sync up.

Since your clock radio has a battery inside, it should keep the time
once it has acquired it.

As I'm not sure how much standardization there is concerning this, the
radio may not be able to set its clock if you are using it in a
country other than the one it was originally purchased in.

William

I should add that it was working perfectly, but recently stopped
working. It used to take the time from the air, no problems at all,
now it has stopped doing that and flashed 12:00 all the time.