Two monitors with LR update - Problem

I use two identical Dell UP2516D 2560 x 1440 monitors driven by a
NVIDIA GeForce GTX 1070 Display adapter. The operating system is the
current 1803 version of Windows 10.

When using Lightroom I do all my editing etc in the left hand monitor
and use the right hand monitor for a full screen display. I have found
this arrangement quite satisfactory for the last several years but,
now, I have just downloaded the latest update for Adobe Lightroom and
have found the second monitor behaving in a peculiar fashion.

The images in the left hand monitor are quite sharp (and true to
color) as usual but the definition of those in the right hand monitor
range from not quite sharp to totally blurry. The results are not
consistent in that if in develop mode I switch from a sharp image A to
image B image B may be blurry one time and sharp another time. And
then image A may be blurry while C is sharp. There is no consistency
in what I can expect.

I use my own images as desk top background and I have found them to
always be consistently sharp in either monitor on every occasion. I
think I can rule out the monitor as the cause. My suspicion is that
the problem is somewhere in the software.

My question is, has anyone else experienced or heard of this problem?
--

Regards,

Eric Stevens