Custom Bonus Action Error

To keep it simple, you can create a new character.

I added a single item, a dagger, to the character.  I'm not sure if that's relevant or not (haven't tried it with nothing yet)

I then create a custom bonus action "Dual Weld Dagger"

I set

range: Melee

dice count: 1

dice type: 4

Damage type: piercing

Activation Type: Bonus Action

Dual Weld: checked

Display as attack: checked

This creates the bonus action without issue.

If I later go back and attempt to set Fixed Value to '0', I get the following error:

Action
character.CUSTOM_ACTION_SET

Payload
{"id":531333,"properties":{"name":"Dual Weld Dagger","toHitBonus":null,"description":null,"snippet":"","isProficient":false,"isOffhand":true,"statId":null,"rangeId":1,"diceCount":1,"diceType":4,"fixedValue":0,"damageTypeId":2,"onMissDescription":null,"saveFailDescription":null,"saveSuccessDescription":null,"saveStatId":null,"fixedSaveDc":null,"actionType":1,"attackSubtype":null,"range":null,"longRange":null,"aoeType":null,"aoeSize":null,"activationTime":null,"activationType":3,"isSilvered":false,"damageBonus":null,"isMartialArts":false,"spellRangeType":null,"displayAsAttack":null}}

Error

ActionApiError: Invalid JSON response, data object is a string at new t (https://www.dndbeyond.com/Content/1-0-587-0/React/CharacterTools/dist/characterSheet.bundle.min.js:23:49323) at Object.r [as validateResponse] (https://www.dndbeyond.com/Content/1-0-587-0/React/CharacterTools/dist/characterSheet.bundle.min.js:23:47922) at https://www.dndbeyond.com/Content/1-0-587-0/React/CharacterTools/dist/characterSheet.bundle.min.js:50:386799 at r (https://www.dndbeyond.com/Content/1-0-587-0/React/CharacterTools/dist/characterSheet.bundle.min.js:23:249497) at Generator._invoke (https://www.dndbeyond.com/Content/1-0-587-0/React/CharacterTools/dist/characterSheet.bundle.min.js:23:250617) at Generator.e.(anonymous function) [as next] (https://www.dndbeyond.com/Content/1-0-587-0/React/CharacterTools/dist/characterSheet.bundle.min.js:23:249676) at h (https://www.dndbeyond.com/Content/1-0-587-0/React/CharacterTools/dist/characterSheet.bundle.min.js:23:124617) at n (https://www.dndbeyond.com/Content/1-0-587-0/React/CharacterTools/dist/characterSheet.bundle.min.js:23:125288)