I have several Inkbird devices all set up in the Inkbird app. I got a new phone, installed the app, logged in and all of my devices were gone. I have to go through setting them all up again now, which is tedious for the 3 smart sensors I have.
Just to confirm, did you previously use the INKBIRD app, not the INKBIRD PRO app or the INKBIRD SMART app?
If you changed from INKBIRD PRO app/ INKBIRD SMART app to INKBIRD app, please understand that due to technical limitations, the device needs to be reconnected.