Laptop Won't Connect With Some Networks

It looks like the Latitude E6400 was launched around 2008 and therefore has an older wifi card.  Try installing the latest Intel wifi drivers and ensure that the Window's 802.11n settings are optimal for the wireless adapter device, for example: http://www.intel.com/content/www/us/en/support/network-and-i-o/wireless-networking/000005544.html

I used to have an older 802.11n-only wifi-enabled scale that wouldn't connect to my previous router unless the router's 2.4GHz speeds were set lower (e.g., "up to 54 Mbps" vs. "up to 300 Mbps").  The Orbi admin website controls don't offer such detailed 2.4Ghz speed settings but I assume it's running at the fastest possible protocols, at the expense of compatibility for older wifi devices like your work laptop.  It may be that the Advanced Wireless Settings options like "Enable 20/40 MHz Coexistence" matter for your laptop so you can try different values and see if it fixes your connectivity problems.

But since you need your work laptop to connect wireless while you travel it's probably worth it to just buy an external USB wireless connector and get modern wifi connectivity for your older laptop.  These external wireless adapters can also upgrade your wifi from 802.11n to 802.11ac speeds.  I purchased a Netgear AC1200 Wi-Fi USB Adapter for my older desktop so it could connect at 802.11ac.  It's only $55 from Amazon: https://www.amazon.com/Netgear-AC1200-Wi-Fi-Adapter-A6210-100PAS/dp/B00MRVJY1G