Originally Posted by
jeallen1 There may have been a text in the past that never sent. Scroll through your list of text messages with this person and see if any individual message has the icon on it.
John
Me too.
Interestingly the failure was a message from 7 weeks ago on my old Sam s5. I got an LG G6 precisely because without WiFi calling and without T-Mo Band 12 I was having a lot of failed SMS in my office. I only noticed the /!\ caution after the Maroney / Staneski debatephone upgraded to Oreo last week.
Deleting the failed message cleared the indicator.