Extremely slow 2.4 GHz network

slow isn't a very good descriptions. some actual speedtests using your 2.4ghz and what device your using can help us determine if its an expected speed or not .

problem with 2.4ghz is that is is much slower than 5ghz and is also more sensitive to interference because there's less channels available in that range. 

for instance, my orbi setup usually sees an average speed of around 20-30mbps over 2.4ghz. sometimes I can peak up to 70 but it isn't sustained. Its pretty much useless for streaming. Reason for this is how congested my area is with 2.4ghz signals. But my 5ghz can hit 500-600mbps. big difference. 

So what speeds are you actually hitting over 2.4ghz?

what device are you testing with? this is key too as some devices are 1x1 antenna arrangements. 

How are you testing? What app/website?