Modem Storage Overload?

Just wanted to chime in as well in case anyone has heard of any update. I live very close to downtown Atlanta (always great phone service and plenty of towers in the area) I recently got T-mobiles Home internet and even with "Weak/Good" signal (since I live in the lower level of a duplex, half basement basically) I still get good enough speeds to stream HD content for myself and my two other roommates. 

After a week or so the internet just kept dropping out during my roommates work hours (8am-5pm ish, and usually he's trying to be on video calls for work so super frustrating). After a few more weeks it was like 5+ times a day. Called T-mobile quite a few times and nothing helped, but I did see that I kept getting the Modem Storage Overload message. 

Tried the obvious troubleshooting (power cycle, factory reset, changed some settings around like using different channels to see if I'd happen to get a lucky fix). T-mobile ended up replacing the router but still having the same issues, just haven't had the message appear yet. 

My more specific question is, could it possibly be my devices/network causing the issue? T-mobile did credit my account after one call since they said they definitely have been having issues between the data breach, too much traffic, taking over sprints towers, and upgrading towers, etc. I'm assuming that a brand new Nokia made router can handle the 20-30 devices I have connected especially since most of them are simple 2.4Ghz lights 'n such, but maybe the firmware installed is causing problems with that many devices? I'm honestly about ready to just splurge on a really nice router to just handle all wifi traffic and plug that into the T-mobile router via ethernet because, 1. I'm out of ideas 😒 and 2. I'm always adding devices so it's probably about time to invest in my LAN anyways 😂