5g home internet - some sites won't load

I am having the same troubles for the last 3-4 weeks when I use duda.co to develop websites.  It is very intermittent too.

I just had the exact same issues the OP had. Have had tmo home internet for 6 months and this is first time it happened. Certain sites wouldn't load, across multiple PCs, phones, browsers, even my roku streaming stick wouldn't connect to certain apps like Hulu, yet HBO Max worked. So definitely seemed pointed to the tmobile service. Yet connecting to my tmobile 4g phone's hotspot made everything work normally. So maybe it was 5g related. The Tmobile home internet app is mostly a joke, basically only things it lets you change if you want 2.4 and/or 5 mhz bands, SSID, and password, that's it. And the vast majority of the time when I open that app it doesn't recognize I'm connected to the modem ("Hmm, we couldn't get you connected automatically...").

After about 12 hrs of having this issue and unplugging modem once to restart with no changes, I was actually able to connect to modem with the home internet app, which I used to restart the device and that did the trick. Back to normal.

Working in Dell PC with Windows 11 pro, YouTube and Gmail work, other websites including T-Mobile.com will not load. Spent two hours on line with tech support. Progressively more technical. For the final solution is they don't know and call Dell. This computer is wired to T-Mobile box not using wifi. Wifi works on phone and tv. I find it funny that it won't load their own site. Kinda tells me it is incompetence and not malicious. 

Any head way on this topic? I have 2 laptops that have the exact same issue as has been described in this thread. I can use both normally on any other network, but T-Mo sites are not loading (see previous error). I can hotspot from my phone to T-Mo and then connect my laptop to my phone and all sites work…. Grrrr!

Same issue here. If I use my mobile hotspot, I am able to load anything. If I use my 5G home internet, I cannot load websites that I use for work. I am running through a VPN. Example website is datadashboard.fda.gov. My IT guy says it appears that it's any site that requires location. I can access these websites through my iPad but not my work laptop that is connected to the VPN. This makes me think it's got to be a setting on my laptop.

I can connect to same websites on other internets. Hotels are fine, even taco bell internet is fine so this make me think it's the internet.

I work from home and live remote so getting good internet speeds it HARD. I have great speeds with TM so I really do not want to switch again.

EDIT: I just reset my router via the T-mobile T Life app and now everything is working as it should.

I had this problem immediately upon activating my T-Mobile Home Internet Gateway, G4SE-1. I could not access my company's website or e-mail servers when connected to the Home Internet Gateway, but I could connect to the domain using a cell signal on my phone or when using a VPN on my computer. I tried restarting the router with no change. My T Life app does not have a reset button, so I used a sim removal tool to push the reset button on the back of the gateway for five seconds to reset it. After the reset, it updated firmware and I had to set it up again, but now it is allowing me to access my company's website. Very odd. I hope it doesn't happen again. 

Update, it has been six days since I reset my home internet gateway, and again, I can no longer access my company's website or e-mail servers. I called tech support and they had me unplug the gateway for 5 minutes and restart it. After rebooting I can access my company's website. Not sure I want to deal with having to reboot the gateway weekly to get it to work.

I also have the same problem with T-Mobiel 5G,  Tried to access “https://passportstatus.state.gov/" and it wont load, but it load on other ISP, also noticed that it wont load on Tello or T-Mobile Cell service either.  had the service for 24 hours and ran into this issue. had to call T-Mobile and cancel it because if one site doesn't work, what else doesn't work that I don't know?!!   I was willing to keep it and was excited about the service and new service but unfortunately canceled it.

What it turned out to be for us - T-Mobile is IPv6 only. Where my wife worked - they were IPv4 only. Can't believe some places are still IPv4 only since IPv6 has been around for over a decade. My wife no longer works for the company and we have gone back to T-mobile 5g internet and everything has been working well. 

From this thread - it appears perhaps many places haven’t upgraded their technology in a timely fashion?

I have done Trace Route from T-Mobile to “https://passportstatus.state.gov/” and it doesn’ Leave the router, last hop is the router but it resolved the DNS.  if I do it from other internet connection, it travel through internet and different hop and it will get there. not with T-Mobile

I even went to the store to return my equipment, sales person tried it from his T-Mobile Phone or store WiFi and didn’t work either, but once tried it from other Internet providers, it worked without any issue. is amazing that T-Mobile hasn’t fix this issue.