I was so annoyed with @jetbrains Rider this morning when it stopped accepting text input. I switched back to Visual Studio and the same thing happened. I guess it’s not their fault.
Sorry to hear that. Did reopening Rider fix the issue? Should you encounter the bug again, please file an issue in Rider tracker and attach the log files to it (Help -> Collect and Show log...). https://youtrack.jetbrains.com/issues/RIDER