Welcome to the community!
Have you tried factory resetting the modem/router and set it up again?
If yes and it is still the same try to use our supplied modem/router if it works you may need to contact the manufacturer of your modem/router.
I went ahead and tried to use your community details to pull up the account unfortunately no match.
Kindly PM me your account details (Username/Customer ID or Contact number associated with the account) and I will run initial tests on your service at the same time.