I had filed bug 1767925, which was closed as a duplicate of this. That bug is specific to the snap on ubuntu. I have switched back to the deb via the mozillateam ppa, purely because of this issue. The deb works fine. The problem seems to be that the snap is not able to find fonts which are on the system but not embedded in the pdf. In other words it's an ubuntu snap packaging bug, not a firefox bug.
I had filed bug 1767925, which was closed as a duplicate of this. That bug is specific to the snap on ubuntu. I have switched back to the deb via the mozillateam ppa, purely because of this issue. The deb works fine. The problem seems to be that the snap is not able to find fonts which are on the system but not embedded in the pdf. In other words it's an ubuntu snap packaging bug, not a firefox bug.