Unable to access on-demand training content

Since at least lunchtime yesterday (13:00BST 26th May 2021), my colleagues and I have been unable to access various on-demand content courses. For some reason it doesn't seem to affect all/previous courses, for example I can access "Information Storage & Management v4" but not "PowerStore : Configuration, Features & Migration" nor "PowerStore : Implementation and Administration". 

This was reported to Dell Education Support yesterday and twelve hours later a response came saying "other customers were having the same problem although some reported it working with Firefox". Since then, nothing. Oh, and it doesn't work in Firefox for me.

Do we know how long this is going to take to resolve please?

Many thanks,