Maybe the other windows have more air movement over the surface as they cool. Do the other windows have trees nearby? Trees may block east facing windows cold night sky radiation so they don’t cool below dew point.
Prevailing winds in your area have been from the S-SW during the last 24 hours. Humidity has been high (in the 80% range) dewpoints in the 50’s. All good conditions for condensation to form on your east facing windows. Call your window salesman and educate him.
I have the same thing on one of my upper east facing windows in my office.
Linas is correct.
#1 Condensation is relative to the temperature of an object subjected to outdoor ambient conditions above the dew point temp of the object that is getting wet.
#2 Why is it one and not others?: When you begin to “think thermally” as Linas is, there are many conditions not obvious to you that can drop the windows temperature colder than the outdoor air.
Why does frost occur when the temperature is not below freezing?
Why does one side of your truck windows frost and not the others?
Look in your first pic.
See the reflection?
That is a hint.
Now, the windows “perspective” may not be the same as yours. So even if other windows can “see” the sky, it may not be the same.
Why the East side?
That is where the sun comes up.
Heat drives moisture.
Solar convection.
You can not see or feel this stuff.
But it can be measured.
Those that think they can find stuff without Thermal Imaging can chime in now with their undocumented opinion.
When you changed your windows to a better thermal rating, it allowed the window be colder than your old ones and now you see proof that the new are better than the old.
Comparison. Very accurate camera correction is required.
To predict when the condensation will form then you must also understand psychrometrics.
Depending upon the amount of latent heat in the outdoor air, will determine if or when it will happen.
Robert, yes that is relevant however please explain when the exact same condition exists at different Windows with different orientations as well as locations are significantly different and the moisture only forms on certain Windows.
Why does frost form on one side window of your truck and not on the other in the wintertime? It’s not about interior airflow then.
This time of the year David may not even have his heat on yet. That’s when the anomaly usually occurs…