Hotspot https problem workaround

I am trying to find a Workaround through the current Problem with Devices not beeing redirected to the captive Portal, because of a https connection of the Clients Browser.
It seems that there is no real Solution which works for everyone using the the Hotspot in Mikrotik,
so I thought that simply using a WPA2 Secret and setting a Bandwith limitation would work for me as well,
but I would need to show something like an Advertisment Page after Login to the Wireless Network.

Would this be possible?

Or, what solution do you have.
Currently I have about 20-30% of our Guests beeing not able to connect to the Internet, because of the https Problem.