What is this strange object?

I’ve started to see this on my form occasionally, seems like when I’m having a big conflict with something or other (Pan X can be full of surprises). It only happens in data entry mode. I can’t make this happen on purpose, but it happens often enough and things seem to come to a halt. Here is what I’m talking about, appearing around a data cell:

That looks like a Text Editor Object in edit mode with the Pop Up Editing option turned on in the Appearance pane . The gray surround is the editing highlight and the tiny single handles along the right and bottom along with the three in the lower right corner are to indicate resizing options.