No Tom, you're doing nothing wrong, it's just your current model showing its limitations at times.
My early Sharp models were like looking through a wire mesh fence at the screen.
An impossible lattice to camouflage.
In those days users actually recommended soft focus to mask the issue! Ha ha ha.
Whaaaat!!
You don't need to spend hardly anything these days to accelerate yourself at least a decade onwards in this technology onto a projector that would have originally cost many thousands giving true HD in a calibration intended only ever for the home cinema arena.
You'll be truly amazed at the difference from what is available in the used market, even at minimal and negligible price points.
The panels and technology utilized, improved beyond belief in a few short years around this point in time.