High power levels cause a range of symptoms: Unstable connections mainly, drop outs and high error rates. If the error rates are high enough then you'd probably find that latency (ping) was very variable, making gaming, streaming and voice or video conferencing difficult. And if the connection is sufficiently error prone or erratic, it could affect speed as well. But it doesn't follow that you'd have all of those symptoms.
Incidentally, if you're using a 15 dB attenuator and you're still seeing 8 dBmV power levels, then (a) you're getting rather close to the 10 dBmV limit for comfort so you might need a higher level of attenuation, and (b) there's a question as to whether your connection needs looking at to move it on to a different tap in the street cabinet rather than just applying industrial strength attenuation at the hub. If all is working fine now, perhaps best to leave for the time being, but when some normality returns perhaps re-ask the question in these forums, and see if the VM staff can advise.
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All wired connections are working fine and download and upload speeds are 350Mbps+ / 35Mbps.
I am having alot of problems with the WIFI. Some devices that worked fine on the Hub 2 are now losing internet access. They stay connected to WIFI but lose internet access saying "Connected with problems" or "Connected. No internet access"
Other devices are just really slow and take forever to load anything when connected to either the 2ghz or the 5ghz. I have disable all the "intelligent wifi and channel changing" but the same thing still happens.