French: number/number regular expression is not picked up

The following regular expression is used to detect number/number in the French language model:
number-fraction;\d+\/\d+

The corresponding lexrep is:
;;{number-fraction};;FRNum;

Example sentence:
On définit l'hypertension par une valeur supérieure à 140/90 mmHg.

Trace output:
LexrepIdentified:140/90:FRCon;

Remark: the same regular expression is used in the Dutch and English model. For these languages 'number/number' is detected as a number.