Thanks for your post and welcome to the forums. It's really great having you on board with us in the Community.
I'm sorry to hear you've been having some slow speeds. Taking a look at your account, I can see most of your power levels are OK. There are a few that are borderline but nothing that would cause the speed decrease that you are seeing.
The hub has been up for over 65 days so refreshing this will help. Please reboot the hub by turning off at the mains and leaving off for a minute or two. This will help refresh things and could improve the speeds.
I can also see that you are connecting via WiFi. You may not get full speeds depending on your environment so these pages will help optimise things for you: