Thanks for the update. Looks like you have a typo you may want to correct; it is Build 22621 not Build 22521. 😉
Still no explanation from MS on why so many users are having problems with this update.
I did several updates to build 22621.232 without any issues.
I also tried using the MS official R.P. ISO 22621 and everything worked fine for me on 3 different machines. 🤷♂️
Christophe Sperandio already posted earlier that the third-party ISO 22621.232 solved his problem.
Just installed it. Got stuck at 5% for some time and then finished in less time than it took to reach the 5% - suspected a fail first - but - unlike other's reports, mine didnt fail (double checked),
22621.232 solved quite some update related issues for me .
Edition Windows 11 Enterprise
Version 22H2
Installiert am 09.06.2022
Betriebssystembuild 22621.232
Leistung Windows Feature Experience Pack 1000.22632.1000.0