Port engine running at lower than usual temperature

[340DA]

The temperature of my port engine of my 2000 340 Sundancer is actually running (lower) at about 155 degrees. Both Strd and Port usually/typically are in sync at 170-175 degrees each. However, the port engine is running lower than usual at 155 degrees. Stbd is at 175.

I have Bravo 3 outrdrives. I cleaned the barnacles off of the water intake and any that were around the props. I'm still at 155

After this, I'm thinking it's either thermostat issues or something else.

Any suggestions to help resolve this issue?

Thanks