Upgrading via one-click upgrade sometimes does not proceed and Matomo stays at the same version, yet there is no error message.
This can be often reproduced on the demo.matomo.org
The update box shows an update is available:
Clicking the box, we get to the standard upgrade screen:
Clicking "Update automatically" leads to the success screen:
It may be an issue only on demo.matomo.org, not sure?
I would very likely say this is only a demo issue and be tempted to just close it until someone else reports it. Also if it sometimes works you can just do it again. Be good if this can be closed or put in low prio backlog since there are more important issues to tackle :)
I notice this quite often with our two instances. Doing a hard reload will bring up the database upgrade and afterwards everything is fine.