Puzzled Texts Delivered Texts Not Delivered

I repeatedly send a text and it’s marked not delivered. Later, I send texts to the same number and it works splendidly. Checked the obvious like I have a connection… restart. Also I have switched between phone and tablet. Just punching “send again” does not seem to work. It’s possible this occurs mostly when I am sending to Android devices.

Maybe the recipient is out of coverage, phone off, doing laundry in the 5rd sub-basement, or whatever? Also, you won’t get “read” receipts from Android, I’m pretty sure.

I’ve eliminated phone off… Gone through Settings and made sure that all my devices are set to send and receive massages. My Mac should work better now but I don’t think that was/is the problem.

It seems to me that my phone was more reliable in sending and receiving… I still hope even though I’m doubtful that the setting changes will do something positive.