Never, ever upgrade until the underlying fault it identified.
Try checking with Area faults on 0800 561 0061 or if you have a VM landline 150 as small local faults are not listed on the VM status page.
Post your power levels and network log from the Hub and post a link to your shared BQM graph.
You could also try a factory reset, as below, on the Hub and do a speed test
Remove any ethernet cables from the Hub and hold the pinhole reset switch for 60 seconds. Do NOT reboot the Hub, just let it do it's thing. Note you will need the passwords from the bottom of the Hub afterwards, so make sure they are legible.
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