Cannot send text messages to Verizon IPhones

I just purchased a new Explorer+. Sync'd the contacts and have also done a firmware update over USB without any problems. I've been trying to send preset text messages to two Verizon IPhone's and they never get received. I have ensured that the Explorer+ is sync'd and phone numbers are correct. Email will go through fine, but the text message never makes it. Is this a similar issue as what is happening to ATT users? I have checked my inbox on explore.garmin.com and can see that the messages make it through there, but never get to the IPhone. Thx.