Ever since the last update the phone have been unable of unlocking and got stuck on the screen with the icon of a lock opening. After several tries it stopped at the failed recovery screen and advices to either delete all data or get support. Any idea what might have caused this and how to fix it?
The phone is a samsung Galaxy 7s
As noted above, those interruptions may cause errors in the boot process. In such case you may need to have the device flashed, which will delete all data... take it to either UBreakIFix or your carrier
In other case, it could be a hardware failure. Take it to UBreakIFix for diagnosis and maybe a fix.
I would normally say submit error report to Samsung Members app but seems you are unable to. If you ever get the phone to boot by luck or whatever then please submit right away for error log collection so the techs can see what caused it.