Re: the MS Teams templates - you can’t use the Web/SDK templates for MS Teams (i.e. rendering menus, images etc). You will need to create a separate MS Teams message using adaptive cards template. Let me know what you’re trying to render and I’ll see if we’ve used a similar tempalte.
For your question re: MS Teams welcome event - I would like to see Kore.ai add this as an enhancement to the platform . We we are not able to execute a welcome message because there is no Event Setting for MS Teams for ‘on connect’.
The only way we’ve been able to do this is via SmartAssist Experience Flow(since we have a SmartAssist bot). However there are still limitations to this. For example, we had to create a custom botkit script so that the Welcome Dialog doesn’t run every time someone sends a message and it’s not simple to maintain.