Clients keep switching to 2.4Ghz after a few minutes

As i said i have seen this message numerous times

And we know you've seen it numerous times. I'm under the impression that you repeat that to imply the issue hasn't been discovered in the community before.

In my personal experience, it's ALWAYS been congestion on the channels/band for 2.4. For 5.4 GHz, you may be using a DFS channel that is not clear. You could be the hidden station in the paradigm and therefore doesn't get kicked. You can find relevant responses in posts from the search linked by @tmomas.

Yeah many things can cause this, seems like...
I mostly see it never on my own devices, strangely?
Only on devices that log into my wifi and it isn't congested or using a DFS channel.
I don't know...