It’s been 24 hours now and the first linux inplace upgrade from fedora 27 to fedora 28 is still working well.
So well that I started more upgrades. The first server (with SSD Drive) completed in less than 15 minutes. It came up well, no issues and continues to run well.
The 2nd server (with spinning SATA Drive) took 37 minutes. It too had no issues and continues to run well.

The 3rd server this morning had problems. Boy did it have problems.
The same process ran fine for the most part.
sudo dnf upgrade –refresh
sudo dnf install dnf-plugin-system-upgrade
sudo dnf system-upgrade download –releasever=28

Transaction Summary
Install 145 Packages
Upgrade 2142 Packages
Remove 1 Package
Downgrade 18 Packages
Total download size: 1.5 G

sudo dnf system-upgrade reboot

after reboot.. it was running a fedora27 kernel.
Linux version 4.16.5-200.fc27.i686+PAE
Try again
sudo dnf system-upgrade download –releasever=28
Before you continue ensure that your system is fully upgraded by running “dnf –refresh upgrade”. Do you want to continue [y/N]: y
Error: Need a –releasever greater than the current system version.

hmm. lets ask the system what it thinks it is
#uname -a
Linux xxxxxxxxxxxx 4.16.5-200.fc27.i686+PAE #1 SMP Fri Apr 27 19:37:12 UTC 2018 i686 i686 i386 GNU/Linux
# cat /proc/version
Linux version 4.16.5-200.fc27.i686+PAE ( (gcc version 7.3.1 20180303 (Red Hat 7.3.1-5) (GCC)) #1 SMP Fri Apr 27 19:37:12 UTC 2018
# cat /etc/*-release
Fedora release 28 (Twenty Eight)
VERSION=”28 (Server Edition)”
Fedora release 28 (Twenty Eight)
Fedora release 28 (Twenty Eight)

# dnf clean all
18 files removed
# dnf clean all
0 files removed
# dnf upgrade –refresh
Fedora 28 – i386 – Updates 10 MB/s | 4.5 MB 00:00
Fedora 28 – i386 32 MB/s | 55 MB 00:01
Last metadata expiration check: 0:00:01 ago on Thu 03 May 2018 12:57:40 PM EDT.
Dependencies resolved.
Nothing to do.

wow. an hour later I think it is fixed… wayyyy too much digging down into the bowels of linuxfedora
rebooted a couple of times, kept having to reset the firewall
firewall-cmd –list-all
services: http ssh
firewall-cmd –add-service=https –permanent
firewall-cmd –list-all
services: http ssh https
That too is fixed.