Just want to chime in and say I have this exact same issue with the speed gauge. I also notice it on both the kFC-150 (the red screen text, not the buttons) and the autopilot annunciator panel. Now here’s the weird thing - two days ago this happened no matter what I did. Then yesterday, everything was clear. No changes to settings, anything else.
I’ve also had this on the A2A Aerostar, so my guess it’s an Asobo bug and not aircraft. It happens to only certain instruments or text, but not others. There must be something common with these gauges or text that makes them blurry. If you look away momentarily and then back the gauges become clear for a few seconds, then go blurry again.