I have a watch face using the scalable BionicBold font which is listed as available on the FR165. This was working fine however a recent software update seems to have removed it, as it falls back to another font which also messes up the layout. No changes have been made to the face, the issue became apparent immediately after updating the watch software.
The font displays fine on the simulator, but not on the FR165 itself. (Tried to insert images but can't post due to "The selected file is not allowed due to file quota restrictions.")
The FR165 is on software version 20.32 (I think it was actually a release just before that introduced the issue). This seems to be the same issue as reported for a few other devices (linked below) but apparently that was already resolved.
https://developer.garmin.com/connect-iq/reference-guides/devices-reference/#forerunner%C2%AE165
https://forums.garmin.com/developer/connect-iq/i/bug-reports/scalable-bionicbold-font-missing