GL-X3000 using Hotspot Data

Setup: I have the GL-X3000 router. Non registered T-Mobile phone SIM. Simply walked into TMO and asked them for a SIM and they basically handed me one without activation fee. $25/mo. Took it home and installed it. Pressed Auto Connect and it was golden. I’ve been using it for about 2 weeks. The router connects to 5G SA and on Band 71. Downloads between 60Mbps and 150Mbps, Uploads between 3 and 9 Mbps. Arcadian Home internet got download speeds close to 10 at most. I’ve tried other Channels and Band 71 gives me the best Download speeds and I don’t need much faster Uploads. However, no Wi-Fi calling on Band n71 when on 5G SA. So to get Wi-Fi calling I have router configured with custom route rules using wireguard to allow ipv4 addresses to devices on the network. Also have ipv6 NAT6 enabled. One last configuration is that I’m using Cloudfare as DNS server to bypass T-Mobiles DNS.

Issue: Just got a SMS message on the router telling me that I’ve used 80% of my Mobile Hotspot Data. It appears that I’ve used almost 200GB of regular data and 80GB of Mobile Hotspot Data. What have I done that would cause the data to be split like that? Could it be the IPv4 traffic going thru wireguard? Not sure if that could even be true since only VOIP data should be using wireguard: 208.54.0.0/16 & 66.94.0.0/19

Do I need to have different TTL settings for TTL and TTL IPv6? Right now they are blank.
Anyone with any insight on this? Your help is appreciated.

TTL should be 65 for both IPv4 and IPv6. That said, it is suspected that the carriers are now able to detect if the TTL “trick” is being used and still count data as hotspot. Sometimes using a vpn can avoid the detection.

I am very curious of what T-Mobile plan you have for $25/month that allows 200 GB of regular data and 80 MB of hotspot data?

Actually, I have a TMO business account. Any additional line is only $25 for unlimited data and 100GB of Hotspot. It is a standard phone line but obviously there is no phone capability with the router other than SMS messaging. It’s basically the same service as their Home Internet plan that they charge $50 for or $30 if you are currently a T-Mobile customer. I did set TTL to 65 last night but haven’t been able verify if it is still using Hotspot Data. Thanks for your help. I will update this thread if I discover anything else.

Update: I’ve now used 241GB of data and 91.85GB of Hotspot Data. TTL is set to 65 for both IPv4 and IPv6. So something is still using Hotspot data but it’s not going up as fast as it was. Still trying to isolate what that data is and how to get it off the Hotspot data. Any suggestion on tools I could use to isolate this data? I’m thinking of resetting all data when my phone plan ends and try to see if it’s a particular device or if it’s just traffic being routed thru IPv4. I only get 100GB of Hotspot data so I suppose if I hit the cap and they throttle it I might be able to see something slow down maybe. TMO has never really throttled me for anything in the past.