If you want to switch from one selected namespace to another, you cannot remove the old one with backspace, you have to add the new namespace (which even doesnt show up pinned at the top), but click out, click in again and deselect the old namespace.
So the current user experience is really shitty tbh, sorry.
Could you provide something like selectize? Easy to remove single namespaces:
Hello h0jezvgoxfepbq2c,
Thank you for reaching out to Lens forum!
I’ll let the dev team related your suggestion.
Thank you for the feedback!
Best Regards,
Tikhon Kudinov
Lens Support Engineer
Mirantis, Inc
I liked the old version. If I click on a namespace, only that namespace is selected and the dropdown closes. If I click on the checkbox next to the namespace, it means I want to select multiple and I have the option to select multiple.
Yes, please 
I have 40 namespaces and my team has had 2 incidents since updating
Hi, in the next version the Namespace selector will not close when a Namespace is selected.
Thank you for your feedback.
This, please this!
I think this is my biggest issue with the new UI. I always have to click twice to switch to a new namespace. I rarely use multiple namespaces at the same time.
The 2nd biggest issue is that the namespace doesn’t sync across the tabs. So every time I need to switch the namespace I have to do the same interaction from my 1st issue on EVERY SINGLE TAB.
Note that if you create a new Tab, the namespace selection of the previous tab is already preselected.
I know, that helps. But doesn’t help when you switch namespaces when tabs are already open, which is most of the time for me.
This issue is already in our backlog and hopefully will be resolved in near future.