for personal reasons, I often activate the preferences window, but it pops up towards the bottom of my screen (13" Macbook) with its bottom half off the screen. I reposition it so it is all visible but the next time I open it, it’s halfway off the screen again. Is there any way you could help this window remember its last (repositioned) position? Or if this is an apple thing, perhaps someone could educate me (I’m willing to be taught)
You mean the one that comes up when you choose Glyphs > Preferences? Mine does remember its position in Version 2.6.6 (1343) on macOS 10.14.6.
The window positions are stored in the app preferences. In case you transferred them once from a different Mac or a different user account, there is a chance that the write privileges got messed up. Can you paste this in Terminal:
ls -l ~/Library/Preferences/com.GeorgSeifert.Glyphs2.plist
And tell me what you get as answer? It should be a line that starts with