Since the last software update there is no checkmark button on the lockscreen. 
Apparently the checkmark was removed and you just needed to type the pin code. But if i type my pin it does'nt unlock the phone.
One user in a post (added the link to the thread) i read said that the software update changed the pin.



https://www.techbone.net/blackview/bv55 ... phone/2317

Hi there.

After every firmware update Blackview highly recommends to perform a factory reset to avoid weird issue like this one.
Please perform a factory reset from the recovery mode, as showed here:

http://bbs.blackview.hk/viewtopic.php?f=192&t=334922

Hi
This is not an option for us since we plan to rollout the bv5500 to our ~200 drivers who are always on the road.

bcattaert wrote:

Hi
This is not an option for us since we plan to rollout the bv5500 to our ~200 drivers who are always on the road.

Updates are not mandatory. If your company uses phones for such business activity, i suggest you to disable automatic firmware updates to avoid issues like that.