This will apply to some 4G phones as well then as the s10+ is such. Thanks community for all the insights. Will try the A71 as well and see if it works because it is on hand and the user relies on simpler tech.
Whoever posted this today, I just want you to know that you are not the only one. It works for me but not for my spouse who has a Samsung Galaxy S10+. They too can send and receive texts but not calls. Curious what you found out.