Group messages with Android and iPhone over Wifi Calling and Texting

I can't receive android/iphone group messages when I'm on wifi calling and texting. The group messages will come through later once I have normal cell service but can be delayed several hours. I have cricket as my carrier are they the issue? Group & MMS messaging settings already checked. I'm hoping someone knows whether it's an iphone issue or carrier issue because I need it resolved quickly. I missed important group messages (about 21 of them) when I was responding to very important matter in a hospital (no service inside) which happens a lot with a volunteer role and I can't continue to volunteer with them if I can't communicate with my team. Thanks in advance!