Adrian Camacho,
is this at a residents? Or office building? If at a residence, are you in an apartment, condo where there are a lot of other WiFi networks around you? Also since you mentioned you have two r300 did you put it on smart channel changing? I recommend you stick to 1, 6, or 11 for channels for 2.4ghz since you have no controller and make sure those two r300 are on different channels and they don’t overlap each other. It’s possible if you left it at auto everything that each r300 is interfering with each other depending how spaced they are apart.
What channels are your 5ghz set to?