Waiting for header long long time and not successful upgrade

Hi, I face upgrade problem. It waits for header long long time and not success in upgrade. It occured about 2 days ago and I tried many method found in google and not help. I also tried with different laptop and different network.
Please help

In Software & Updates, try switching to Main Server under "Download From".

Your local regional server may be down for the past couple of days.

I also selected the best server and not help

Where did you make this selection?

Instead of selecting "other" just select Main Server.

selected main server still got probem

I am on main server. I just ran sudo apt update and had no connection issues.

You might try

sudo apt --fix-missing

and see what output it yields.

Have you added any repositories recently?