Same here. This was my same experience from a Transit Duo purchased through Mobile Must Have with Envision Serivces. I’m told my device is also blacklisted due to it being “stolen”. Device was purchased new from MMH and used the ATT service referred by MMH from day one.
So, I’m looking at spending another $1K to get a transit Pro. Quite frustrating.
sorry that you’re dealing with the same thing. Seems that they’re definitely cracking down on resellers. I’m not sure why devices get reported stolen unless that’s how the resellers cover themselves or something. Based on my conversations they all seemed to indicate that it was reported stolen and that it wasn’t fraud automatically flagged by their system which was why they kept saying it was out of their control.
I‘m still up and running so there’s definitely a fix. Took me about a week of calling repeatedly asking to talk to managers and eventually they supposedly opened a case on it and I have them all of the reseller info including the APN they had me use.
The FCC complaint seemed to be what really got their attention but even then I had to find the right person who could help. Multiple people from the office of the president reached out in response to the FCC complaint. One guy still tried to put it back on me and tell me that I was the one who put their SIM in my device and that I should have vetted them better. I said yeah that’s true, but that there needs to be a way to resolve it since Bix in my case was the shady reseller and that me as a consumer and rightful owner of the device shouldn’t be at fault. Finally someone followed up and said they had to run it through the fraud department to get the block removed and surprisingly it’s been working since.
It seems like it is through the IMEI of the modem. I have 2 SIM slots also but only one IMEI. They kept getting confused because it seems like internally the modem is a Sierra Wireless board which is how it shows up in their system even though it’s a Pepwave device.
So the best advice I can give is keep persisting if you have the patience and another source of internet in the meantime. Definitely file an FCC complaint. my complaint was saying that it’s ridiculous that consumers have no recourse in situations like this and that nobody at AT&T was willing to offer any type of solution to help resolve the issue. I also filed FCC and BBB complaints against the reseller just for piece of mind I guess.
Gold luck to you, it’s definitely not a fun situation. I always knew resellers were shady but didn’t think the device would almost become a brick after trying one for a month. I just wish there would be a plan that offers a reasonable amount of data even if it means paying for it. I’ve just been using multiple prepaid SIMs and haven’t had issues swapping them out with the same modem.
I filed an FCC complaint and opened a case with AT&T Fraud. I will let you know if it is resolved. AT&T Advance Technical Support cannot permanently unflag IMEIs that cause this problem. Only AT&T Fraud can. MobileMustHave has done NOTHING to help even though they caused the problem in the first place. We will have to spread the word about them I think. Sad.
I now have an AT&T Business Wireless plan that is great when it’s not suspended. There is apparently restrictions on streaming but I didn’t experience this. I’m going to have a second AT&T Consumer plan (100Gb for $55) as a backup once my router is “cleared.” I’ll then manage the type of bandwidth for each of the plans so that streaming doesn’t cause a problem. I also have a Verizon plan that I use in the second sim slot.
hopefully they’ll get you unblocked here soon. Yeah Bix straight up ghosted once I reached out about the blocked device. They didn’t even notify me once the plan stopped working, I emailed them and they surprisingly cancelled and refunded the balance.
I personally can‘t wait until Starlink is a suitable mobile option. Sounds like it’s getting close so hopefully in a year or so i can switch over and forget about cellular plans 
Point of clarification. But first an update. AT&T Office of the President called me and took the information (because of the FCC complaint). I’m waiting for their response.
Regarding the blocking. It’s important to recognize the difference between an IMEI sweep/block and the DEVICE being flagged by AT&T and blacklisted. When the sim is in the router and it doesn’t work, it’s because the PLAN has been suspended due to the IMEI issue. For example, when my plan didn’t work in my MBX router, I moved it to my MST router and it still didn’t work. But, after I had AT&T unsuspend the PLAN, the sim did work in the MST router and continues to do so. It’s a two-step process; 1) sweep IMEIs, if flagged 2) suspend AT&T plan.
So just remember that when you move the sim to a different IMEI, be sure that the PLAN is not suspended. Earlier in this thread, it’s apparent that there was some confusion about why the sim didn’t work for a non-blacklisted IMEI - it’s because the plan had been suspended.
Nuf said. 
Ok so I’m having the same issue. I got into contact with AT&Ts fraud department and they told me that there is a contract between peplink and at&t and because peplink discontinued the contract at&t is blacklisting peplink devices running at&t. Seems wierd to me but I will keep calling at&t to see if I can get it resolved. Really rediculous that I did my research and found a device that my needs and spend the money on it only to have this kind of issue with no support from the manufacturer whatsoever.
Same issue as in you used Bix wireless?
Brave, two years later, are you still up and running, or have you upgraded your device by now? If you have upgraded, id be curious to know did you stick with Peplink, or move on to another provider?
I am 3 weeks into precisely the same issue as you, although involving a unit originally purchased through RV on the GO (now part of TechnoRV).
The irony is this issue didn’t surface until the monthly service with the 3rd party was replaced by a ATT sim card and Verizon Sim card purchased directly through the carriers directly for $$$ savings. I would like to hear from you.