Monks can use either Strength or Dexterity for unarmed attacks or attacks with their Monk weapons. The D&D Beyond sheet will automatically select for you the higher bonus.
You can use Dexterity instead of Strength for the attack and damage rolls of your unarmed strikes and monk weapons.
Just rolled up a quick monk char and the monk weapons and unarmed attack are using Str instead of Dex for damage modifier
Is this a bug?
Monks can use either Strength or Dexterity for unarmed attacks or attacks with their Monk weapons. The D&D Beyond sheet will automatically select for you the higher bonus.
Maybe I'm misunderstanding the rule. Does the modifier to damage include the proficiency bonus?
appreciate the help
Damage does not include proficiency. (at least not by default or in any case I can think of).
Tali_Wah is correct. You do not add your Proficiency bonus to damage unless instructed to by a unique feature/item.
Can you link the character if you have more questions?