Neural filter did not do anything, and then pop-up never came back

I tried to use neural filters to stylize a layer using Style Transfer. The layer was an image on transparent background.

I wanted to use my own image as reference, so I selected Custom, loaded my image, selected destination as current layer and pressed OK. The only thing that happened is that the image was selected with the ants outline, the neural filters pop-up disappeared and I could not bring it back. I tried to choose it again from the Filters menu but it never came up. I had to close PS and restart.