Ethernet, cat 6 cable, i also tried cat 5e cable. I am doing my tests on speedtest.net
I am worried if I decide to take up a more faster package like m500, the problem will transfer over, and I will still be stuck on around 250-300mbps. I tried contacting support, but they kept repeating the minimum speed guarantee.
They said, we can't send an engineer out, because we dont see any faults.
Can you post your Hub status and logs? Someone should be spot if there is a problem Navigate to http://192.168.0.1 (or http://192.168.100.1 - if in modem mode) Don't log in! Click on 'router status' Copy/paste the data from each of the tabs as text into a 'REPLY' as opposed to 'QUICK REPLY'. The forum software will remove the MAC addresses for you (you will likely need to click the 'post' button again).
Also, set up a 'Broadband Quality Monitor'. This will monitor the state of your connection and record any network dropouts etc - You can do this at ThinkBroadband (https://www.thinkbroadband.com/broadband/monitoring/quality) Give it a while to gather data and then click 'Share Live graph' and paste the 'Direct Link' into the forum!