Font check error for `sTypoLineGap`

Glyphs
1

I am running a font-bakery check on my ttf files. And I am getting one error in the report that is difficult to understand. Here’s the log:

{
"description": "Each font in a family must have the same set of vertical metrics values.",
"key": [
"<Section: Universal>",
"<FontBakeryCheck:com.google.fonts/check/family/vertical_metrics>",
[]
],
"logs": [
{
"message": "sTypoLineGap is not the same across the family:\n Bold: 280\n Light: 220\n Medium: 250\n Regular: 235\n SemiBold: 265 [code: sTypoLineGap-mismatch]",
"status": "FAIL",
"traceback": null
}
],
"rationale": "\n        We want all fonts within a family to have the same vertical metrics so their line spacing is consistent across the family.\n    ",
"result": "FAIL"
}

What is sTypoLineGap exactly and how do I set/correct it?

2

This is a setting to define vertical metrics: https://glyphsapp.com/tutorials/vertical-metrics