Yeah, not unexpected . They all handle the feels like differently, I have seen this as well, you might want to go look up the general consensus on line.
Some just use the heat index , some do something weird, some have their own that includes wind chill, etc. Deal is , really not a bug, just the way it is reported, which is the jurisdiction of whatever system is reporting it.
I get it, frustrating. But you can, if you want, use the data provided , and go calculate your own, Big PITA.
Personally, I like the items provided separately, heat index, wind chill , etc..