I had a similar issue. I am on android (Samsung S10+) and tried
everything I could find online. Was in touch with visible tech support
and we ultimately resolved it by resetting the network settings (Search
for "Reset Network Settings" in the setting...
Just resolved this issue on my end and wanted to post here so others can
try this as well. Problem: Using android, Samsung S10+. After switching
carriers to Visible, MMS messages no longer were being sent or received.
They would show up as downloads ...