This has been going on for several months and I've just recently had the time to troubleshoot it.
I have a Samsung Note 10+ 5G. It's difficult to replicate the problem while I'm contacting support because it occurs intermittently. I have contacted Verizon the last 4 days in a row after each of their suggestions didn't fix it. Posting here because the last 2 days the support agents were rude, declared my issue resolved and ended the chat on me.
I'm in a group chat with 4 friends that also have Verizon, 3 of them have iPhones and one has a Google phone. The delayed texts happen intermittently, and seem to occur when we are all texting back and forth right after another, my texts in the chat don't go through right away, there's a spinning circle like its processing, and I don't get any texts that my friends are sending. Sometimes my texts just won't send and I have to keep trying to resend. The delay can be anywhere from a half hour to several hours. This occurs no matter my location, my zip code is 95136. Eventually I get everyone's texts in separate individual texts that I have to download, and once downloaded they show up in the group text (not in order). One of my friends said it was happening to them when they had a Samsung phone and stopped now that they have iPhone.
Things I've tried, that I remember:
Having Wi-Fi turned off all the time
Switching from Verizon Messages+ app and now use Samsung default messaging app
Resetting network settings
Clearing cache and data from the apps
Verizon support agent said they synced my phone to Verizon
Force stopping the app and restarting the app
Restarting my phone
Turning my phone off and leaving it off for 3 minutes before turning back on
Deleting the group text and then creating a new group text
Turning on Safe Mode
I have several group conversation happening as well and would be concerned too if I were having any issues with sending messages. Is this only happening when trying to send messages? Or does it happen also when receiving messages? What signal is your phone showing at the top when this occurs?
It occurs when on 4G/5G with good quality of service as well. This is a known Samsung Issue WITH NO FIX. If you have a legitimate fix please share with customers.