There is one limitation to running Powerline adapters, and that is the electrical circuits must be on the same phase. Meaning, the remote end and where you plug in the other adapater inside the house, both need to be on the same phase. If not, it won't work.
The reason that some people have problems with them is that both adapters should be plugged into plugs that are on the same side of your house's power box (which my garage and shed are).
This is true...so just a heads up to anyone using PLA's that plug them in, find that they're running great and some time later they're not, it could be because they're NOT on the same leg of 120/240 (split-phase 3 wire ). The reason why they worked initially is because a 240 volt device or appliance (electric water heater, electric clothes dryer, HVAC) was operating and that coupled the 2 legs, usually capacitively and enough to establish reliable communication for the 2 PLA's...as soon as the 240VAC device switched off, the PLA's lost coupling between the 2 legs and no more communication. There are coupling devices available but they are hard to find, not cheap and just one more active component to fail, especially in areas with high lightning activity causing power line surges.
So if you go the PLA route (and I've used several reliably for years), as stated by @weigle
and others, insure they are plugged into receptacles fed by the same leg (same side of the breaker panel, left or right).
Regarding Ubiquiti and TP-LINK, I use both extensively...Ubiquiti radios for my P2P layer 2 transparent wireless links and ceiling AP's (UniFi) and TP-LINK for PLA's, wireless routers and ceiling AP's (Omada AC-1350)...just depends on the situation.
Wednesday I installed a Ubiquiti P2P wireless bridge between two metal-skinned and metal-roofed buildings 200 feet apart; building #1 has Internet and I sent it to building #2 and installed in that second building a TP-LINK wireless router operating in AP-mode for the occupants.