Related with the blue double tick (i guess), i haven't change it, so got default.

Send message to contact, double green tick shows, close chat, contact respond, open chat, the double green tick is now grey tick.

Let me disable and check.

Greetings.

Edit: I fact, doesn´t matter, once when you close the chat window and open again, the double green tick change to grey (with or without the blue tick enable/disable).

Don't know if the other person have the double blue tick enable.

Edit 2: The x is typing doesn't work for contacs either, and green/blue ticks shows as far you have the chat open, when you close and open again, shows grey tick.