macos big sur download stuck when completed

Found the possible solution here on the forum:

1. After download reaches 12.18GB and get stuck, disconnect internet connection and then download will stop.
2. Connect network again and click "upgrade" button (you will notice that the download is not anymore at 12.18GB but is not also starting from the beginning maybe it will be half downloaded and starting from this point).
3. And then after some time will get stuck again and you do the same 1 and 2 steps above and you will see that the download is growing little by little I did this 3 times.

Thank you, Ella! After trying so many things, your solution of repeatedly clicking Upgrade, each time it stopped, worked for me. It did, however, take about ten times due to my very slow internet. But every time I clicked upgrade, it jumped to where it had left off. At one point, it read that it had reached 12.20 but the blue bar was not full, and it hung there. The numbers were inaccurate. I had to disconnect from the internet and reconnect to get back the Upgrade box and click it again. It resumed at around 10.0 and finally made it all the way. Due to my slow internet, it took over eight hours. But I'm so relieved. Thank you.