Might be the agent pushing to find customer

If you really want it...just register through online or in this forum..rattan can help you

This should be a typical VIP10/BIZ10 speed. 10Mbps is about 1.25MBps while you're downloading at 1MBps. If and only if you're on VIP10. Besides that, there may be unhealthy seed, causing you unable to hit full speed.
Just reboot it. Or you can choose to switch to TP-Link or asus. I'm now using TP-link TL-WR841ND. So far so good. It can sustain 15 days no downtime(no disconnection at all) and someone else showed 29days no downtime. It's just RM80 if you can make it to lowyat to buy it. Other places should be around RM85~100.
When I'm using that DIR615, I'm really fed up. Reboot at least once a day because me and my housemate are having quite heavy usage. It just can't handle well. Sometimes the signal just gone crazy, totally disappear from my housemates' laptop. Few of them can't detect them at all while others still manage to online. Weird enough? Yeah... xD
My suggestion, get a replacement router.
1. Check your email you used to register UniFi. I received an email for that.

2. You can choose...
i) Homeplug @ downstair -> Homeplug @ upstair ->Switch ->Two desktops
But you need to know whether your wiring from downstair to upstair is in phase

ii) Another router to do wireless bridge upstair. Then you can connect both desktops through LAN to that router

iii) Two wireless adaptors. Mind you, don't buy from TM. Theirs is quite crappy. Another thing I worried about is that the wireless router given by TM might not have signal strong enough to reach your 1st floor. "Might not", not 100% cannot.

Anyway, it's not mandatory to have desktops and TV in the same floor but you need to do the wiring/other alternatives in order to connect them.
The setup is basically

FTB -> BTU ->phone (DECT)
..................-> DIR615 -> STB

You also need to know from where the fibre will be pulled into your house in order to plan the setup.
Btw, welcome to UniFi family