Non-latin character non spoken by espeakup

[Didier Spaier]

Hello,

in Slint text installer with:
kernel 4.19.17
espeakup-0.80
espeak-1.48.04

In a Linux console, when a language uses
non-roman characters, only the roman ones
are spoken.

e.g. running :
espeakup-Vel

What can be wrong?
What can or should I do?

Best,
Didier