problem with Forum display

When I select this Google group, roughly half my screen goes to one
display format and larger font and differnt colours, and the other to
what I am accustomed to with this Forum.

Now, I don't mean half and half screen either vertically or
diagonally,
but PARTS which are always rectangles; possibly 10 or so with 5-10
lines height and mainly on the right side..This is only the last two
days.

Anybody else sees this?

After about 1 second it all goes normal and stays so.

Another point.
I posted a reply yesterday; it doesn't show up where it shoul, but the
NEXT posting has somebody else who saw it, use it to copy and post a
further reply. So at least PART of this is Google and not just my
computer.
.