Does the code whisper work? When writing Serial.print, for example, it doesn't offer me anything and I have to write the entire code.
When I type "Serial.p", and then a "Enter", then I get "Serial.println".
That does not help for me, I can type "Serial.println" faster than looking at the screen and seeing what is proposed.
Arduino IDE 2.0.0-beta.11 in linux.
There are some known issues and limitations. You can see the formal list here:
and you'll also find quite a few other informal reports in this forum category.
There are some boards that are not supported.
You need to make sure you have a board selected for it to work.