Can no longer pick up local channels. Any ideas why?

In the US, those radios are in the GMRS band and difficult, although not impossible for a business to use. The whole idea of GMRS and FRS was for citizens to have radio channels to use. While GMRS frequencies need to be Licensed by the FCC for all users, businesses are not usually allowed and a Taxi should not be on those channels. You could call the FCC, make the Taxi company
prove they have a legal license.

If you are picking up local only, you will need to set your tv channel to channel 3 or 4 in order for your interfase box to work

Are you trying to still tune an old TV to pick up analog channels over the air? Analog OTA broadcasts no longer exist.

Called manufacturer

first of all, make sure all your connections are secure and threaded all the way in. Next, go to the main menu and press 5 (configuration) and press 1 (search for channels) if this doesn't work, press 4(signal strength meter) and see how strong your signal is. You may just need to re-position your antennae. If all else fails try system reset(number 5) and repeat search for channels. I've had similiar experiences with mine but I have a 62% signal strength and still get 20-something channels. Hope this helps.

u may need a special signal enhancer that u can purchase online or at an electronics store....otherwise u may need to consider basic cable

I have the same box and re-tuned mine with the same results as you.However i discovered that the NEW BBC channels were on the channel guide list starting at channel 800

might need new codes

Yes if the unit is capable of picking up cable, there is a channel setup menu in the main menu. You half to switch it over to the cable mode. it should be in the owners manual. Good Luck