I have reported this bug multiple times in the Pro Discord. The power of Rage Fist is not being boosted correctly. If a Pokémon uses Future Sight and then switches out, and Annihilape takes the Future Sight damage, the power of Rage Fist remains at 50. It should increase to 100.
I first encountered this bug a couple of months ago, and I ran into it again yesterday. I had an Annihilape at +4 (equivalent to two Swords Dances), and when I used Rage Fist against Zapdos, it dealt less than 50% damage. It should have dealt over 90% if the power had been boosted correctly. I can share the replay in private message if required.
Kindly look into and fix this bug.