Unfortunately, LG IMS has stopped.

Clearing the data in com.lge.ims.rcsprovider as detailed above worked for me this morning but not yesterday.  This seems to clearly be a T-Mobile generated problem which may have been fixed overnight.  Maybe LG had something to do with it but I doubt it since they haven't updated the OS since 2019.  In any event, most of us bought the phones from T-Mobile in the first place.  Snafus happen.  The question becomes how does a company handle it.  Many people were greatly inconvenienced by this issue.  I wasted hours yesterday on ineffective fixes including phone resets and have spent more time today undoing those ineffective fixes.  If T-Mobile had acknowledged the problem early and just said "be patient, we working on it" it would have saved an awful lot of bother.   I get a lot of unsolicited texts from them all the time.  It would have been nice to get something useful!  Many, including me were considering buying a new phone and some undoubtedly did.  Today, I*'m still considering a new phone, but also a new carrier, even though I've been with T-Mobile well over 20 years.  If they want to treat customers right, they should issue an apology and offer something such as a free month of service to those so inconvenienced by yesterday's FUBAR.