Keynote font display bug - OTF font typeface is transiently changed in open presentation (reverts when file reopened)

I have presentations that uses Latin Modern OTF (v2.005), which are installed in Font Book and located at `~/Library/Fonts/lm*.otf` (e.g. `lmroman10-regular.otf`). Sporadically, the display of the font will change.

Keynote will spontaneously decide to switch the typeface from "10 *" to "5 *" (e.g. from 10 Regular to 5 Regular). This appears to be a transient display bug; if I close and reopen the presentation, Keynote will revert to the correct typeface — in order words, the switch to "5 Regular" is not saved into the file, it's just some glitch in how Keynote is handling the saved information. This is also clear when I copy and paste the affected text into a new presentation - if I copy text that should be "10 Regular" but is displaying as "5 Regular" into a new presentation, it pastes as "10 Regular" (other styling eg size is preserved too).

Every instance of an affected fontfamily-typeface in the presentation will switch at once, but not all fontfamily-typeface combos appear to be affected. E.g., in the attached screenshots, the left column of text is not affected while the middle and right columns are. The left column is Latin Modern Sans 10 Bold Oblique and 10 Bold (both stay at 10), the middle is Latin Modern Roman 10 Regular (displays as 5 Regular), and the left column is Latin Modern Sans 10 Oblique (displays as 5 Oblique).

I have tried reinstalling the LM font, verifying the font with Font Book, and clearing the Font cache. Nothing seems to work.

Any help is greatly appreciated.

Correct display:

Transient display bug: