I regularly encounter a bug in both PvP and PvE where if I hit an enemy while I have solar fist/melee charged I will only cause burn damage instead of the initial melee base damage and the burn damage that's meant to accompany it, especially annoying in PvP as it will always make you lose the fight. It's always either both damage potentials or just the burn damage never just the melee damage which in PvP it is preferable. Hopefully you can replicate it in your tests and fix the problem.