Message reply issue

Just an FYI
Here of late am running into problems responding to a personal message.
On occasion I’ve tried to respond to one and there wasn’t any box to reply.
Today I have a box to input my reply but it indicated no permission and said log in was needed.
Have iPhone. Tried logging in, and clearing the cache. No go.
I can create a new message and send it. But not respond to an existing chain of messages.
No deal breaker. Just weird.

 

Have you tried to respond using a PC ? It may be an issue with the phone app.