Hello,
I have had just the same problem. I think it is caused by the last
security upgrade by unattended-upgrades of these packages:
gir1.2-javascriptcoregtk-4.0
gir1.2-webkit2-4.0
libjavascriptcoregtk-4.0-18
libwebkit2gtk-4.0-37
in the unattended-upgrades mail that informed me of the upgrade,
needrestart-session added that:
User sessions running outdated binaries:
didier @ user manager service: bwrap[2629], evolution[2417],
gnome-session=
-b[2185], systemd[1956]
Log ended: 2023-05-04 09:35:34
So I restarted my gdm session (and thus Evolution)
And since then, Evolution does not show email bodies
It seems to me to be a regression bug likely caused by the upgrade of
one the four packages above (I have done a dpkg-reconfigure of them,
without success)