Swapping phones on Metropcs network.

So I had to switch from T-mobile to Metropcs and I used to be able to switch my sim card across multiple devices. Now I've got 2 unlocked oneplus ones and an unlocked GSM Samsung Galaxy Note pro 12.2 LTE and the sim is only working in one of my oneplus phones. When I switch the sim into the other oneplus phone it won't even recognizes it as if it's a foreign sim. I downloaded an exposed module called imei changer and changed the imei on my other oneplus phone so that it would have the same imei number as the phone that works with the sim. The imei changed successfully and I checked it with several imei checker apps and it was the working phone's imei but same thing still happens. Metropcs says they would register only one phone per sim. I already called them and asked for help.
I'm using the latest cyanogenmod 12s on my oneplus.
Any ideas?