[masraum]

Originally Posted by BK911

Im on a well.
Debris routinely clogs up the screens in fixtures.
Finally installed an inline filter at inlet
Clean it once in a while and all is well.

Second the water pressure gauge.
Pretty cheap for one the threads on hose bib.

This is the one that I got. It works well.
https://smile.amazon.com/gp/product/B07T9ZPJKZ/

Are your showers 2 knob or one knob showers?

Many modern one knob bath/shower faucets have an anti-scald valve built in, and when those go bad, the pressure often drops, so that's a possibility.

I think you can get an adapter to screw the pressure gauge onto the shower head pipe.

If the screens on your sinks occasionally clog, I assume the shower does too, and you've already checked/cleaned it.