I guess I have fixed this problem for my 5s.
1/ make the backup in tunes
2/ turn off «where is iphone» in iCloud preferences.
3/ restore iPhone to factory settings. you have to sacrifice ALL all your information. you get a brand new device. in my case, this step was successful only after 4-5 effort with an error.
4/ restore app from backup. phone asked if I wont to use backup and mention that it is only for apps and other users stuff like the photo, not for OS. i agreed. 🙂 it takes some time and patience. finally, all my apps, photos, preferences had resurrected. thank god and apple! you have to enter lots password/codes/numbers again. but it is the biggest problem you face.
After previous 11.2.6 update with reload-bug i had 4-figures unlock password.
This time OS ask me for 6-figures password. Maybe previous time 11.2.6 update was not installed completely.
Now I have tested all my app more than an hour and any reload. Hope that all.