Can you try logging out and back in please and see if that works?
Edit
Regarding the tabs, it may be worth starting a feature thread and we’ll take a look. However, there may be a way of doing it with custom scripts. I’ll take a look and come back to you shortly.
Edit 2
When click a linking, using either Ctrl and click the link, or use the scroll wheel of your mouse. However, remembering this can be a bit of a issue (especially if you’re like me and forget!)
To enable it for the ‘Impersonate Client’ button, you can use the following code:
$(".page-clients-detail #btnimpersonate").attr("target", "_blank");
});```
You can add this to your custom scripts under Account Settings > Design Customisation > Advanced CSS & HTML Customisation
Hope that helps :)