I'm in exactly the same situation. I've done all the steps and the pinhole resets, Bluetooth on and off, app uninstall, cache cleared, phone reboot, reinstall, etc, with no luck.
I was connected and working fine for over 2 months. Tried to add my daughter to the sesame and ran into difficulties setting up her account and then after somehow getting her account set up, wasn't able to add her. (No longer said her email didn't have an account, but just spun when adding her email address). So I decided I could just uninstall and reinstall the app, right? That's supposed to work for an existing phone or a new phone. I figured maybe the app data was corrupt.
But upon reinstalling the app and logging in (that still seems to hang and then "work" later), the app said I had no Sesames in the account. That seemed strange since I figured it was supposed to download my credentials for my Sesame from the Candy house servers.
Did the pinhole reset and for awhile the device showed up in unpaired Bluetooth devices as "Sesame", but now it's just a device with no name. Sesame app sees the device ID, but doesn't let me connect in the app.
Solutions? Was happy with the Sesame despite its idiosyncrasies (slow to connect sometimes). Would like to get it working again.