Problem with Greek tonos followed by consonants

Hello, can somebody help me please with the following problem:
I have a Greek charakter set in my font and detected a failure with tonos accent. When writing tonos by mistake in InDesign, followed by a consonant, tonos behaves like a non-spacing accent and clashes with the consonant.
Unless acute etc. which spaces correctly. for example: έ Ά = correct and combined; ΄Κ ΄λ ΄Π ΄δ = not correct and should not be combined
In Glyphsapp preview everything works fine, but it doesn’t InDesign or TextEdit.

Hello again,
is there a possibility to change tonos from non-spacing to spacing?
The goal is to have tonos typed as a separate character when followed by a letter without diacritic combination (as acutes do).

There was a wrong definition in the Glyph data base. I fixed it.

You can fix it with a custom GlyphData.xml file with this content:

Please see this blog post about the details.

Thank you, Georg, I followed your hint but the issue is still the same.
A quick compare with Minion Pro shows up that tonos is set Nonspacing, but behaving correctly.
So something seems to be wrong with the tonos in my fonts. May I email the files and could you have a quick look? If yes: the glyphsapp files or better otf?

I just tried it and adding the GlyphData file solved it for me. Did you restart Glyphs?
The tonos in the Minion on my system is set up as spacing.