4g Signal Extremely Slow

Morning. I switched to ID from Plusnet (Now EE) about a month ago. The internet speed is legitimately unusable. The majority of the time, as the data rates are so low, websites and services such as speedtests will simply time out. I bought the mid-tier data plan, but at the current 4g data speeds I wouldn’t even be able to use all of the low-tier data plan if I left the phone on and consuming data 24/7 for the entire month.

I’ve added screenshots of my current data rates, when I can get speedtests to work, which isn’t too often.

Any ideas on resolution? I already factory reset the phone, as it wasn’t picking up my new number at first. Tried using the sim in other phones too, but it’s still useless. My partner has an ID sim too and her’s is the same. Coverage of my area is indicated as good, and it’s not that I don’t have signal, it’s just unusably slow. 

I’d rather not go through the headache of switching providers all over again when I just switched, but I'm not sure what else I can do at this point.

Many thanks.