Thanks, it would really help if someone could reproduce this issue, enable dev mode and see Network tab and XHR requests, so that it’s possible to know what’s happened.
If the error is not reported, ideally with steps to reproduce it, how to expect to fix it? And let me reassure you that it is NOT a global issue. PS Checkout performs well, and such global issue would’ve been disastrous.
You may like or not PrestaShop SA solutions, but the team is really responsive and determined to help if there are issues.
Regarding PrestaShop 9, we plan to release patch version approximately every 6 weeks. Considering that Update Assistant is a solid choice to update from one version to another, especially for patch versions, that should help with v9 adoption.
We are doing our best, also with amazing community members on GitHub, to make PrestaShop 9 a solid foundation.