I think that uninstalling the app has indeed caused you to no longer be able to see the lights in Homey.
Have you linked many lights, sensors and buttons from Hue to Homey?
I’m afraid you have to add everything again. Maybe first remove the app from your Homey and then add it again and add the lights in the setup of the app?
I think you have to log in to Philips Hue again and then you can add the lights again and hopefully the flows will also take them over if the lights have the same names.
I have a lot of lights and sensor and cant find any. How do I log in Philips Hue from Homey?
If I just add lights in the devices tab no such option appears…