display size issues

I apologize if this is a redundant question, but I have tried various suggested solution to increase the guest screen size with no luck. Here is my environment:
Windows 10 /x64 host
VBox Version 5.2.22 r126460 (Qt5.6.2)
vbox guest 5.2.22
I have attached the VM log file. Other vbox guest addtion functions are working (share mouse, clipboard, etc.). Any guidance on this issue is appreciated,
Thanks!
Leor
Windows 10 /x64 host
Linux localhost.localdomain 3.10.0-957.el7.x86_64 #1 SMP Thu Oct 4 20:48:51 UTC 2018 x86_64 x86_64 x86_64 GNU/Linux
[root@localhost leor]# cat /etc/*-release
NAME="Red Hat Enterprise Linux Server"
VERSION="7.6 (Maipo)"
ID="rhel"
ID_LIKE="fedora"
VARIANT="Server"
VARIANT_ID="server"
VERSION_ID="7.6"
PRETTY_NAME="Red Hat Enterprise Linux"
ANSI_COLOR="0;31"
CPE_NAME="cpe:/o:redhat:enterprise_linux:7.6:GA:server"
HOME_URL="https://www.redhat.com/"
BUG_REPORT_URL="https://bugzilla.redhat.com/"
REDHAT_BUGZILLA_PRODUCT="Red Hat Enterprise Linux 7"
REDHAT_BUGZILLA_PRODUCT_VERSION=7.6
REDHAT_SUPPORT_PRODUCT="Red Hat Enterprise Linux"
REDHAT_SUPPORT_PRODUCT_VERSION="7.6"
Red Hat Enterprise Linux Server release 7.6 (Maipo)
Red Hat Enterprise Linux Server release 7.6 (Maipo)
VBox Version 5.2.22 r126460 (Qt5.6.2)
vbox guest 5.2.22
I have attached the VM log file. Other vbox guest addtion functions are working (share mouse, clipboard, etc.). Any guidance on this issue is appreciated,
Thanks!
Leor