Panel not respecting field names that start with underscore (_)

I am using a Machine Learning automated translation service to translate my content.txt files. I wanted to use an underscore prefix naming convention for my blueprint fields when they are to be ignored/excluded from processing by the algorithm.

e.g. a field like this will be ignored:

  type: multiselect

e.g. a field like this would be processed:

  type: text

As soon as you make an update throught the panel, it replaces the _Key: with Key: despite the fact that my field definition in yaml has an underscore ( _ ) prefix. Note, the _ is not being replaced with - either, e.g. -Key:, which is what would otherwise happen when a field has an underscore in the middle somewhere; it’s just being removed.

If I rename the keys directly in the content.txt files manually – e.g. Catgories:_Categories: - everything is fine, the Kirby PHP methods work etc., method chaining is fine, API endpoints fine, everything is fine, so it seems not be a problem for the Kirby API to work with the _ prefix, but the Panel is renaming my fields regardless.

The Kirby documentation for blueprint field naming says I should be able to use alphanum and underscores, so not sure why is this problematic? Bug?