Hello there Leonard,
Hope you're doing well.
Basically, you are adding feedback-message-autoclose class to your message, which has an attribute called animate-duration of 5s. This is the reason why your message closes automatically after 5-7 seconds.
Addicionally, it is important to mention that Info and Success messages have this extra class by default, while Warning and Error messages don't.
Nevertheless, please consider to use this component: https://www.outsystems.com/forge/component-overview/9691/feedback-message-utils-reactive
It has already that logic implemented considering both cases, so you just need to add it as a dependency to your module :)
I believe that you want to use this client action:
ShowFeedbackMessageWithTimeout
As an example (info message with a 20s duration), it would be something like this:

Kind regards,
Rui Barradas