some command may be useful, but it's clearly beyond average ....

# dnf history list
# dnf history list sogo

many components / packages maybe involved, gnustep-base, gnustep-base-libs, sogo*, sope4*

if you have epel.repo be also very careful it likely conflicts with the one (gnustep*) from Sogo

You are right! Problem is gnustep package.

I solved the problem and I want to share the solution (was not so easy).

Unfortunately I update gnustep-base from Epel repository. A big mistake!
At time of writing Epel version 1.28.0, SOGo/Inverse version is 1.24.9.

Uninstalling Epel version is not enough.

Step I used to resolve:

1) Backup your SOGo configuration file located at /etc/sogo/
2) Make sure to exclude unwanted package from Epel repository in /etc/yum.repos.d/epel.repo
    (exclude=gnustep* ytnef*)
3) Uninstall Sogo, Sope and other related Package
    dnf remove  sogo* sope* gnustep* libwbxml* lasso* libobjc* libwbxml* memcached* ytnef*
    (probably dnf will remove other dependant packages)
4) Manually remove (or rename .old) folders not removed by dnf/rpm
    rm -rf /etc/sogo/
    rm -rf /usr/lib64/GNUstep/
    rm -rf /var/lib/sogo/GNUstep
    rm -rf /usr/lib64/sogo
    rm -rf /var/log/sogo
    rm -f /etc/sysconfig/sogo.rpmsave
    rm -rf /usr/share/doc/sogo
    rm -rf /usr/share/doc/gnustep-base-libs
5) Reboot your system
    shutdown -r now
6) Reinstall SOGo
    dnf install sogo sogo-tool sogo-activesync sogo-ealarms-notify
    (dnf adds the necessary dependencies including the right gnustep/ytnef packages)
7) Restore config in /etc/sogo/
8) Make sure /etc/sogo/ files is owned by sogo user and group
    chown -R sogo:sogo /etc/sogo/
9) Make sure log files and folder are owned by sogo
    chown -R sogo:sogo /var/log/sogo/
10) Start services and test
    systemctl start memcached.service
    systemctl start sogod.service
11) Enable services at startup
    systemctl enable memcached.service
    systemctl enable sogod.service

I hope I haven't forgotten anything.

Thanks you all!
Carlo