This morning (~5:30 UTC) I noticed that umlauts (e.g., ä, ë, ü) no longer work in Firefox 60.8.0 esr (64-bit). They were working 24 hours before. I have not updated the software on the systems I tested in the period I observed the issue.
Details on the problem: when I type umlaut-accented characters (e.g., ä, ë, ü) on the text field of exercises, nothing is displayed. I’ve been practicing the exercises of the German courses. I use a US keyboard layout with dead keys. Umlauts work everywhere else in the system, including everywhere else in Firefox, except text fields of exercises in Memrise since this morning.
The operating system I’m using is Debian GNU/Linux. I tested in two computers, one with Debian 9 (stretch) and another one with Debian 10 (buster). Same Firefox version on both systems. I can reproduce the problem in both systems. I tried restarting Firefox, but the problem persists.
Needless to say, this issue is very annoying, as I have to resort to using a mouse to click the umlaut-accented characters on the screen.
If you need more information, please don’t hesitate to ask.