error of service unavailable

[super1234]

I can't update my s21 plus system software it just shows me service unavailable every time I go and check for software update. Can anyone tell me how to fix it I also factory reset my phone

[rizw6n]

Check if this phone status is official or custom.

[super1234]

It is official

[rizw6n]

What was last update received on your phone?

[super1234]

How do I check

[rizw6n]

When you check for the new update, on same page go in the 3rd option.you will find the details of your last update.

[super1234]

This one