@Appart52 While Airbnb is often unfair to hosts, in this case, I understand why this was registered as a host cancellation.
I don't know which of your 3 listings this was, but one of your listings has a check-in window of 2pm-2am, one from 2pm to 10pm, and the new listing says "from 2pm."
That means guests should be able to check in anytime during those time periods. And just because a guest gives you an ETA of 2pm, doesn't mean they have to be there exactly at 2pm. All sorts of things can slow people down when travelling.
These guests were responsible enough to let you know they'd be an hour late. It wasn't okay that they were denied access only 45 minutes past the original check-in time.
Unless you have informed the guest when they booked that you won't be able to check them in except during a very small window of time, and made sure that will work for them, it isn't okay to tell them that they can't gain entry during your posted check-in times.
If you need guests to check in exactly between 2pm and 2:30pm, then change your posted check-in times.