We definitely want to get to the bottom of this ASAP! We will be sending you a Private Note, so we can further assist you.
I've been experiencing a similar problem with my "hotspot". Well after tens of hours of troubleshooting, on hold, doing research... it turns out that it's a slow data connection.
Have you tried checking the speed of the network while your having problems? Try FCC speed test, which is a free app available at your app store. I've found it helpful for a variety of reason but most importantly, it confirmed that I wasn't getting anywhere near the 4G LTE speed that I have been paying for.
I'd love to hear what you find out. Unfortunately, you may be unpleasantly surprised.