LB2120 SMS alerts failing but testing works

I setup this modem a few weeks ago and it actually works great as a failover.

Using Mint Moble (T-Mobile infrastructure) and the only thing I cannot get to work is the SMS alerts when the Spectrun wired link fails or when data usage goes above what I have preset for an alert.

Now, the strange things is, testing SMS manually works great both ways (instantly) so I know the network and my LTE plan works fine.

Have done a couple of factory resets but no cigar. I am using it in bridge mode with an EdgeRouter 4 and failover and fail back works flawlessly, just no SMS alerts of any of the activities one can select to be alerted on.

Open to any ideas here.

Thanks!