gparted - Libparted Error, unable to inform the kernel of the change

Question

This is on CentOS Linux release 7.6.1810 (Core) with gparted.

I'm trying to re-format LaCie rugged external drives connected via USB 3.0.

I continue to get this error message when using gparted to format and add a partition:

    Libparted Error
    Partition(s) 1 on /dev/sdf have been written, but we have been
    unable to inform the kernel of the change, probably because it/
    they are in use. As a result, the old partition(s) will remain in 
    use. You should reboot now before making further changes.

By default, I noticed through the GUI it automounts the drive, but I have unmounted it from the command line before I proceed. Makes no different, I get this error message.

I have tried rebooting and trying this again, and the same thing.

How could I find out what is causing to generate this error message? It seems to think the resource is in use by another process, but I don't know what they could be.

I ssh'ed into the server and ran this:

while :
do
sleep 1
lsof | grep sde
done

So I could monitor if the device sde was being accessed. Although my message originally was for sdf, after rebooting, it got assigned to sde.

What I found out is, that gparted is access sde. When I clicked to "apply" this I saw this in the lsof output:

gpartedbi 7504                root    6u      BLK               8,64       0t512       16537 /dev/sde
gmain     7504 7506           root    6u      BLK               8,64       0t512       16537 /dev/sde

So it seems that gparted and gmain itself are accessing sde, which I would expect it to do since it is formatting it. But I don't see anything else.

I do see this in the log regarding systemd-udevd. Is this related?

Sep 18 14:04:13 myserver gparted.desktop: ======================
Sep 18 14:04:13 myserver gparted.desktop: libparted : 3.1
Sep 18 14:04:13 myserver gparted.desktop: ======================
Sep 18 14:04:14 myserver systemd-udevd: invalid key/value pair in file /usr/lib/udev/rules.d/59-fc-wwpn-id.rules on line 10, starting at character 26 (';')
Sep 18 14:04:14 myserver systemd-udevd: invalid key/value pair in file /usr/lib/udev/rules.d/59-fc-wwpn-id.rules on line 11, starting at character 29 (';')
Sep 18 14:04:14 myserver systemd-udevd: invalid key/value pair in file /usr/lib/udev/rules.d/59-fc-wwpn-id.rules on line 12, starting at character 25 (';')
Sep 18 14:04:14 myserver kernel: sde: sde1