Display issues in font view

I experience every now and then a strange display behavoir: Sometimes it shows me only the four first lines, the rest is empty. Another times the category names are unreadable. I experience this already for quite some time. Restarting glyphs usually helps, but not always.

If you can reproduce it, we can fix it.

It has been around for a while, and we have not been able to reproduce it so far. A restart always fixed it for me.

This often happens when resizing the window. It gets messed up. The only solution I found: Save and then Revert. All looks perfect now.