Another tab is already working on this error

This morning as always I have more issues with making changes to your site.

1. I am now unable to make any changes as I am getting an error "Another tab is already working on this" when no other tab is! I have tried different browsers too.
2. All morning the page editor tool has been glitchy. Nothing is rendering correctly and to add 3 blocks this morning it has taken me 3 hours.

This is the second time I have given WPMU a chance and all I have is constant issues.

I have specifically taken a day off work to work on my site. I have been waiting for live chat for over 20mins despite it saying I'm first in line and will be answered in 7mins.

Additional to resolving my issues immediately I do ask that I do not get charged for this month. I have to now take another day off to work on my site because your application doesn't work.
Regards,
Manoj