Thanks for posting and a warm welcome to the community.
I appreciate your query in regards to the wireless light flashing on the Hub 3 and apologies if this is causing you any inconvenience.
With the light flashing this could be an issue with the wireless connection or the wireless channel that has been selected, however you have mentioned the signal is working ok.
Have you tried to change the wireless channel to see if that will stop the light from flashing?
Let us know how you get on
New around here? To find out more about the Community check out our Getting Started guide