Text Messaging Issues between Iphone and Android users

Ever since switching from Verizon to Xfinity Mobile I can no longer send/receive group text messages from a mix of phone users (Iphone & android). i have no problems sending group messages to all iphone users. I also cannot send anything but text to any non-iphone users (no pictures, gifs, etc). It's very frustrating. Have had several chats & calls with Xfinity and even went to the store without any resolution. Was told at the store that they were putting a ticket in to have my number looked at to see why this was an issue & that I would receive word in 72 hours. It's been 8 days and there's no phone number to call the store to check solution. Anyone been able to successfully resolve the text message issue or is my only option to go back to Verizon?