That software link via YT seems to have a lot of others having rendering issues. That's Data. Two choices is either you run Ethernet from where ever you wired router from base and you can run Ethernet outside the house the cable can take up to -1F for you the -xx c since you don't use F measurement. Gigabit to handle more data for rendering these cad drawing. This is option. WiFi load on these data rendering of huge cad drawings might require more from the hardware you have right now. Some WiFi Routers are better than others. DIR-655 wasn't made for such task. The A3 hardware is what I was using for a very long time. It's limited.
If you got a older home built in 1700 to 1900 era or something modern as you didn't say which one you have. Got work around this. I use to live in house built in 1920 with underground garage, attic some hidden room. Ran the Ethernet cable outside through vents and back in from the Window. Temp range from 100F to -1F no issues. Also RAN 3x WiFi AP to manage the WiFi. Those results are posted on SNB and on my ATZ http://androidtabletzone.the-talk.ne...ng-discussions
for LAN stuff.