I found a bug in the ts5 client version beta60.2. If you poke someone who is not in your current channel, the poke including the sent message, will not be shown to you in the server chat with that person. Once you switch back to the same channel and poke again, the message will be shown for yourself.
I got really confused whether my poke has been sent or not.
We had s similar report before but could not reproduce this.
I tried your way but it opens the server chat to that user and when clicking on it it shows the poke in there.
The only reproducible issue we found is that the user is shown as offline when he created a channel. That is a know bug for us.
I found a reproducable way for my poke bug. It only occurs, when the person your are poking, have not had a conversation with you this day, ergo the message “Conversation started: Today” is not yet shown in the server chat with that person. The first poke you sent is hidden for yourself and the other ts5 user in the server chat.