@Carmen156
Hosts are aware of the fact that Airbnb transfers the money the day after a guest has checked in.
So if a guest books today for a trip 5 months down the line, the guest pays now and the host only gets the money in 5 months.
It's how Airbnb is set up.
And if your reservation is listed as confirmed by Airbnb on your account, then that is proof of your payment and your host will also have your booking showing as confirmed. You don't have to prove anything outside of that.
Frequently though, new hosts start out without really being familiar with the system, so maybe that is the case for the confusion...
Hope this helps.