Custom Values Shown as "Unknown object (?)" in Herald Maniphest Tasks on editing (not creation)

If I have custom maniphest fields: e.g.

“custom:mycutomfield”: {
“name”: “Custom1”,
“type”: “select”,
“options”: {
“Apples”: “Apples”,
“Oranges”: “Oranges”,
“Lemons”: “Lemons”
},
“default”: “Apples”
}

Then create a Maniphest Herald Rule (Global)

image

Using those fields

Save the rule, (all is good) - (and the rule runs correctly) and the description is correct

image

However if I edit the rule:

image

Then the custom fields show up as “Unknown Object (???)”

I can even remove the fields:

image

and the description updates correctly.

image

My version is trunk (updated just now) - I have a few minor alterations but not in this area from what I remember.

image

Possible bug?