Hi @Truckwomanshana - I miraculously got a solve! As mentioned earlier, I did all the troubleshooting - off/on, cellular data off/on, mms off/on, reset network settings - no go. However, I came across the following article:
https://www.airdroid.com/file-transfer/iphone-wont-send-pictures-to-android/
In this, it recommended turning airplane off and on. I did this from settings, however didn't help. I followed the instruction on this link and turned airplane off and on from the control centre view - & for me it worked?! I'm on SE 3rd gen.
I have no idea what I'm doing, but I'm posting this as it's been very frustrating. Hope it helps someone!