Who I have the same questioned this topic

Since about end of July beginning of August, I to can not send a regular text message to a friend of mine that has Metro PCS either using the Verizon App or the default app.  I can only send MMS to this friend.  Verizon says it's on their end yet PCS doesn't show anything on their end either.  I can receive their messages and everyone else's message and I can send sms messages just fine, except to PCS yet they can receive sms messages just fine from other Verizon friends.  I've tried factory reset, new sim card, etc....but nothing has worked.  Most annoying !