Mr. Levy-Rossi,
I did not see this problem yet.
Somes questions, however:
* are you using the same InDesign version on your workstation and on
the server?
* how did you install the fonts on the server? With a Windows legacy
workflow (by installing them in C:\Windows\Fonts) or through the
uProduce Dashboard?
* what type of font is it? (TrueType? OpenType? Type 1? Other?)
* have you noticed a difference between Proof and Process on uProduce?
* have you tried to produce some PostScript (instead of PDF) and
either Distill the PostScript, or try to print from PostScript?