Message in chat appears multiple times and in wrong order

I'm facing issues with chat feature. I recorded a video showcasing what I mean.

When I write "Hi there" for example it appears multiple times but only when at the same time I receive a message from someone in the same chat.

Example:

10.00: User B sends "This is a new message" to User A.
10.01: User A sends "Hi there".

This is how User A chat looks like:
User A: Hi there
User B: This is a new message
User A: Hi there

--> "Hi there" appeared first even though it was sent one minute after message "This is a new message" from User B
--> "Hi there" appeared two times, one time before and one time after the message from User B even though it was only sent once

I hope my explanation is clear. Please see the video for more details.