A new window is opennig with the title Remote Office but the rest of the page is white, the Pulse secure logo is in the top right corner. Unsing windows 7 or10 with Explorer or Edge, I get connected to my PC.
Re: White window when connecting from Chrome on Ubuntu 18.04
Seems like you're accessing Terminal Services bookmark, which will work in Windows by using PSTSC client. Non-windows OS would fallback to use Java plugin, per my understanding, Firefox/Chrome have removed Java plugin support.
Please check with VPN admin and see if they can configure the RDP machine as HTML5 resource for you, so that you can use any OS to access it.