Solved with a workaround
> -
> \setupnotation[footnote][way=bypage]
>
> \definecounter[authornote][way=bypage]
>
> % taken and adapted from
> https://www.mail-archive.com/ntg-context@ntg.nl/msg56637.html
> \define[1]\authorNote{\bgroup%
>\savecounter[footnote]%
Hello list,
this is an example of footnotes with two different markers (and counters):
numbers for editor's footnotes, stars for author's footnotes.
The footnotes are typeset together, in the order they appear in the text, so
number and star markers are interspersed.
The two counters are reset
