Escaped slashes in keys are not understood

[Mailaender]

quicktype -s schema http://purl.allotrope.org/json-schemas/adm/lc-ms/REC/2023/09/lc-ms.tabular.schema 
Error: Key m~1z not in schema object at http://purl.allotrope.org/json-schemas/qudt/REC/2023/09/units.schema#m~1z.

excerpt

"m/z": {
  "$asm.property-class": "http://purl.allotrope.org/ontologies/result#AFR_0001868",
  "$asm.pattern": "quantity datum",
  "allOf": [
    {
      "$ref": "http://purl.allotrope.org/json-schemas/adm/core/REC/2023/09/core.schema#/$defs/tQuantityValue"
    },
    {
      "$ref": "http://purl.allotrope.org/json-schemas/qudt/REC/2023/09/units.schema#/$defs/m~1z"
    }
  ]
},