New first time watch owner: two issues

I’m a new watch owner. First time. Third generation SE. No problems for several days. Now two issues, one of which has resolved itself, but I would like to know what was going on. Immediately before these issues showed up I turned off “always on.” Also I just updated the OS:

1) The watch keeps asking me to sign in with the four digit security code. Like every few seconds.

2) A green light on the back of the watch was flashing. Then stopped flashing but stayed on. As I started composing this note the light turned off.