I just raised a bug report over here: https://app.roll20.net/forum/permalink/11384819/. My past history with that forum has trained me to be caututious with expectations, , so I'm asking here, has anyone seen anything like this and do you know a workaround?

For the record, here's the full post:

I haven't seen this reported before. I have noticed when creating a sheet worker with any _max attribute, it does not create the newValue and previousValue properties.

For example, create two inputs, textareas, or spans, one for the normal attribute, and one for the _max attribute

<textarea name="attr_example"></textarea>
<textarea name="attr_example_max"></textarea>

Then create a simple sheet worker

on('change:example change:example_max', event => {
    console.log(event);
})

Then enter anything in the example box, both example, and examplee_max events fire (as normal), but their contents are different:



If you enter anything in the _max, you see the same thing.

The lack of a value in the _max box means it is impossible to caclulate the magnitute of changes, or the direction of changes. This is important stuff!