Can't read names of templates

I have LO 6.3.4.2 from the PPA on Xubuntu 18.04, on a computer with a UHD display (3840x2160). I have several dozen personal document templates, but when I try to open a new text document based on a template the popup dialog box is unreadable. For some reason, instead of just giving me a list of my templates, the dialog box is populated with an enormous thumbnail for each template, and the thumbnail is so big that it obliterates the name of the template. And the thumbnails all look practically the same, so I can’t choose a template based on the appearance of the thumbnail. To open a new text document based on a template I have to open a document based on a random template and, if it is not the template that I wanted, I have to close the new document and try another template, one after the other until I finally hit the right template.

I looked all over the preferences and can’t find any way to change this behavior. Can’t I just have a list in the popup window? Help!