Fenix 6 not connecting (as a HR sensor via ANT)

Just a day ago I made a short ride without the Polar H10, so I quickly turned on HR broadcasting on the fenix6 and it connected to the Edge Explore 2 automatically (It was previously paired).

But today I wasn't a able to get them connected. I also tried it a few times when we had stops, but it didn't connect.

Obviously I can't say for sure whether the problem was on the fenix6 or the edge side, but since I've ran many times with fenix sharing my HR to my running partner I tend to believe the problem was on the edge side.

And again, Murphy's law works: as I got home and tried again it did connect...