The NavStax radios I added to my custom FSX 2D panel for the Carenado Mooney M20F are behaving oddly. They seem to be trying to resize themselves. They change size, disappear and reappear. They do not do this when displayed on a 3D panel. I'm using the KT742D and KX1652D radios and it happens with both of them.

make sure custom gauge not over other gauge.

I'm pretty sure none of the gauges overlap. I used the NavStax Configuration tool to create a radio stack panel and the new panel worked fine. Then I added the radios to my main panel using FS Panel Studio and I get the behavior.

Adding it by hand to the main panel isn't something we can support I'm afraid. The only suggestion I can make is leave them in their own Panel window.

That's unfortunate. I will request a refund for the product.