It could be a hardware issue that happened at the same time. Not likely but it can happen. Or it could be the reset image is corrupted somehow. I would try WDRT and then do the updates again after that.
I think I'm leaving Microsoft world! I loved my Lumia 640 xl so much, I was in insider programe, phone worked great, so I decided to by Lumia 950 xl to make things go even better.
But, this phone is so bad! And Microsoft isn't helping.
I went trough WDRT dozen times, factory software version, than 14393.1066, and when phone comes to 15063.297 things go bad.
Believe or not, I have put my phone in fridge to make it cool enough to continue installation. Finally, phone looses a half sensors, like compass, light sensor, inclinometer etc. . . On day light I cannot see the screen, if I check voice recorder and audio routing to external speaker, any attempt to start or receive a call ends with phone restart. Booting phone is ages long, 2-3 minutes. In the beginning SW reset solved this problems, but how the days passed, this cure does not help anymore.
Long boot means no sensor detection, short boot means all is OK. Now I have not short boot anymore.
I'm thinking, because phone works good on older SW version, this should not be a HW issue. Maybe this critical overheating causes errors during installation. Only regular problem that follows this phone from start is overheating and battery drain. My wife's Lumia 640 LTE keeps battery for 3 days!. Lumia 950 XL cannot stay alive 20 hours, on discrete use. All background process, mail checking, battery hungry apps, everything is reduced maximally but phone has some internal life that burns him crazy.
Anny reasonable help, please!!!!