Oil pressure sender?

97' 220,000 rotella t6 and napa gold filter.

So typically my engine runs at 40 psi while cruising and 20 psi hot idle but lately it has gone down one notch, 30 cruising and 10 hot idle, now what I'm curious about is this a sign of a failing sender or is the tube that it goes into the engine clogged and giving a smaller psi reading? Just seeing what you guys suggest

Test the oil pressure with a mechanical gauge.

It's PROBABLY the sending unit. Dealer sending units work best. But it could be the dash gauge or the elbow.

Seen numerous sending unit failures. Cheapest answer.