Side menu disappears after a few seconds

[WVW]

Hi

I have just installed PS ver 1.7.7.3 for the first time and am trying to configure all the various aspects of it but the menu on the left side is not fixed like in earlier versions of PS. The menu appears for a few seconds when I click on the prestashop hyperlink top left and then  disappears before I can click on any option.

I have done a search on this topic and found https://github.com/PrestaShop/PrestaShop/issues/22250

but this is not applicable to my setup!

Can someone please advise how I can prevent the menu to disappearing?

Thanks