Most likely the broadcast from the TV station stopped or was switched to DVB-T2
If you only use the antenna and the TV, you received analogue signals. Eventually the broadcast cancaled this and switched to digital signals which you can only get by using a set top box or a HDTV with such an integrated receiver.
You can have a look at this site, which TV signals you can get:
https
/www.tvfool.com/index.php?option=com_wrapper&Itemid=29
enter the zip code of your location and it should return a result