D&D 5e Character Sheet makes changes on it's own

Brief summary = Player's character sheet has a spell with an attack roll that is supposed to have charisma mod added to damage rolls, it keeps reverting itself to nothing.  My game = Dungeons of Drakkenheim [EB] Character = Aurora nov Sleeks Spell = Eldritch Blast. Damage type 1 is supposed to be 1d10 + Cha. Player and I both keep changing it but it reverts randomly every other week or two. Using the default 5e sheet, not the new one yet. 

Hi Erik Bjornharta,  How are you making the change? Via the Attack or via the Spell?

Making changes on the attack buttons on core page. It never even occurred to me that if the spell on spell sheet isn’t changed it might refresh from that. Thanks for the idea. I’ll test that. 

I can tell you that it is exactly that.  Attacks derived from spells are generated off of the spell. When changes are made on the attack they will someday revert because the spell tells them to.  Erik Bjornharta said: Making changes on the attack buttons on core page. It never even occurred to me that if the spell on spell sheet isn’t changed it might refresh from that. Thanks for the idea. I’ll test that. 

Gauss said: I can tell you that it is exactly that.  Yes, 100%, I took this advice, ran with it and in the many sessions since, the problem has resolved itself. Thank you very much for pointing out what I missed.