Group messages not coming through

Both my husband and I have been having issues with group texts not working within the app. It shows that something is coming through as a download, but nothing does until hours later. I have missed out on multiple plans for work and group meetings because nothing comes through. We are both having this issue both while on our data plan and at home on WIFI. We still have 2.5 GB of data left with 1 day in our plan, so its not like we aren't running out of data. And we have full signal where we live. We've tried un-installing and resetting the app, still doesn't work. Is this a known issue or are we being pushed to upgrade our phones?

Re: Group messages not coming through
Customer Service Rep

Messaging has become a vital, main part of daily life, emworcester. We will do all we can to help find out why your devices are showing “downloading” for an unacceptable amount of time in your group messages. You’ve taken some great steps so far, and we appreciate that detail. When did this start happening? What text app are you using? What happens with standard texts, calls, and data (apps and Internet) on your devices?