My internet is extremely slow for a while now. I'm currently on a M200 Fibre Broadband but I'm only getting fraction of advertised speed. I've tried to contact tech support but apparently they are closed due to covid.
Could you access your router using http://192.168.0.1/ or http://192.168.100.1 for modem mode . You shouldn't need log in, select the 'Check Router Status' option and paste your 'Downstream', 'Upstream', and 'Network Log' tabs?
I'm not sure how many changes you've made to the hub settings since acquiring it, however I would suggest trying a full reset (Pin hole for at least 30 - 60 seconds). Keep in mind this will restore the hub to factory defaults (Password to sign in, etc.).
You either have a faulty hub or a very noisy line.