Just tested what I think you are saying.
1. Loaded 4 images.
2. made second image active then dragged the layer thumb for that image over onto Image 1.
The image did a copy and paste as new layer so that image 1 was now hidden by image 2.
3. Made image 1 active and added a new transparent raster layer.
4. Dragged the thumb of that transparent layer over onto Image 1
Received the error message saying that the clipboard does not contain any visible data.
But strangely enough the layers palette now showed two transparent layers.
5. Repeated 2. for a third image.
I now had a complex with 2 image layers with two transparent layers between.
6. Dragged the thumb of that bottom image (Image1) back onto the Image 1 complex.
It made a duplicate on top of Image 1 which remained active (in effect did the same as making first layer (image1) active and the doing Duplicate.
Then I looked at the text problem
1. Loaded an image.
2. Loaded another image and typed some vector text in it.
3. From the layers palette dragged the thumb of the Vextor text over onto the first image.
PSPX9 (10.0.1.

crashed
This worked OK in PSP X7 and X8.(18.1.0.67)
So perhaps another bug in PSP X9 if many others can reproduce .
Strange tried to correct but 8 + ) seems to give a smiley

Systems available Win7, Win 8.1,Win 10 Version 1607 Build 14393.2007 & version 20H2 Build 19042.867