Hi,
According to the Oracle Grid Infrastructure 19c documentation the UEKR5 kernel 4.14.35-1818 should be compatible:
https://docs.oracle.com/en/database/oracle/oracle-database/19/cwlin/operating-system-checklist-for-oracle-grid-infrastru…
However, when attempting to install the AFD driver with latest kernel version 4.14.35-1844:

From what I understand, 1844 is a patch level and there is no good reason why it should invalidate kernel driver compatibility. The same issue does not happen with UEKR4 and the AFD Filter driver works with 4.1.12-112 as well as 4.1.12-124. I could switch to the previous 4.14.35-1818 kernel, but what's the point?
Here's what I do to downgrade to UEKR4, since I not need UEKR5 in particular (running in VirtualBox):
grubby --set-default /boot/vmlinuz-3.10.0-957.el7.x86_64
systemctl reboot
yum -y remove "kernel-uek*"
yum -y install yum-utils
yum-config-manager --disable ol7_UEKR5
yum-config-manager --enable ol7_UEKR4
yum -y install kernel-uek
systemctl reboot
This is perhaps an oversight by the 19c GI Installer, but maybe someone from the Oracle Linux team can inform whoever is managing the Database distribution.
Thanks!