missing characters

[Wolfgang Engelmann]

In my lyx document (Koma script book) under no TeX (via LuaTX) I get 
these errors:

Missing character: There is no 𝜇 (U+1D707) in font 
[LibertinusSerif-Regular.o
tf]:mode=base;script=latn;language=dflt;+tnum;+lnum;!
.
<argument> ...rdinate) and growth rate ($\mathrm {\mu m/sec}$
                                                   , red, right 
ordinate) of ...

Missing character: There is no ˜ (U+0098) in font 
[LibertinusSerif-Italic.otf]:
mode=node;script=latn;language=dflt;+tlig;+tnum;+lnum;!


Missing character: There is no 𝜓 (U+1D713) in font 
[LibertinusSerif-Regular.o
tf]:mode=base;script=latn;language=dflt;+tnum;+lnum;!

I use

Version 2.4.0-beta2 (Sonntag, 11. Dezember 2022)
Qt-Version (Laufzeit): 5.15.2 (Plattform: xcb)
Qt-Version (bei Erstellung): 5.15.2
OS-Version (bei Erstellung): Debian GNU/Linux 11 (bullseye)
Python-Aufruf: python3 -tt

/usr/local/share/lyx2.4.0/

and have set mostly "use default"

Wolfgang