Any update on this?
I have the same problem. I set the kerning between brackets () and the zero to -45, but the right bracket sticks to -75. I use FontExplorer and do testing in InDesign (with metric kerning). I have already tried multiple exports as OTF and TTF, updating the metrics of every glyph, renaming the font file, emptying my cache (including restarting my computer) and using the Adobe Fonts folder, in between which I have always quit and restarted all the software used.
Please help me!
Update 1: After updating Glyphs to the latest version (2.5 1131) at least both the brackets stick to the same value: -75. But still: it’s the wrong value. Is there something I’m missing here?
Update 2: It seems as if the values were getting calculated against the values of the capital O, which are set to -30. I am using a kerning group based on the O, which I also applied to the zero. But in this case (with the brackets) I had unlocked the zero from the O’s values, and thus Glyphs let me apply individual values to the zero, which were working fine. Only after exporting they were messed up. I have now worked around the problem by removing the zero from the O-kerning-group, but this does not quite feel like an actual solution to the problem. Do you get any thoughts on this?