@Woodsnasty 

Thanks for screenshot and speed test results. Results are dissapointing, indeed. I know Satellite M5 can do better.

When they sell you WiFi mesh and promote its benefits, they skip the part about importance of proper placement of Satellite units. Satellite unit relays WiFi signal from (usually) Main unit, and as such must be placed close enough to Main unit and also close enough to where you need good WiFi from Satellite unit. They (often) give you only very basic tools to see if placement is correct and no help in the app to find what is wrong when it is.

Usually Medium signal should be good enough for better speeds, but perhaps Satellite M5 is close to borderline between Weak and Medium signal. 

As such, to help figure better Satellite M5 placement and perhaps how many Deco units you do need downstairs, please run two more tests with same setup of laptop hardwired with Ethernet cable to Satellite M5:

1. Place downstairs Satellite M5 right under the office Main Deco M5. This will be the shortest distance between two Deco units on different floors. Check Signal level, is it still Medium or now Strong, and then run speed test on laptop to see what will be the speed of WiFi backhaul there;

2. Place downstairs Satellite M5 as near TV as possible, ideally on TV stand. Check Satellite M5 Signal level there and also run speed test on laptop there.

Please also tell me the following:

1. What floors and ceilings are made of: wood, concrete, etc.?

2. Brand name and model name of TV. Smart TVs are notorious for bad handling of WiFi mesh, so if you want solid streaming quality on TV its brand and model name could help me to find if there are options to achieve that.

3. When you place Satellite M5 right under office M5 in first test, what is the distance in feet/meters between Satellite M5 and TV, and also are they in direct sight of each other or there are walls between them.