Hi, can you please explain what is the actual issue here is?

When you mean this message

The first thing is that we enable the updates from the update server please check: joomla/update.joomla.org#145

As mention in the other issue when the update server allows you to update from 3.10 to 4.0 the pre update checker comes up to me:

Feel free to check it yourself by using this patched version of the update server: https://www.jah-tz.de/downloads/core/nightlies/next_major_list.xml

Please note that 4.0 also requires 5.6 as database version and at least my xampp still runs with 5.5 please double check that when the update / pre update checker does not come up.

OK - I must have done something wrong with the local xml (which I had updated) as it works correctly with your update server.

Thanks for your patience.

Now I can write the code to fix the a11y on that page

Great thanks for the update ?