Can't update/install libraries or boards

Current IDE version: 1.8.9

Current additional urls for boards/libraries.

https://adafruit.github.io/arduino-board-index/package_adafruit_index.json
https://dl.espressif.com/dl/package_esp32_index.json

Libraries/boards affected: all.

Issue: I get the "downloading library" message, but it stops there. Progress bar doesn't move further.
After that, Cancel, close or buttons doesn't work. I have to close Java from task manager.

I delete the files on %Appdata%/Local/Arduino15, and the generated .zip in /staging/libraries with 0KB size. I repeat the process to download, but get the same problem.
Tried uninstalling and re-installing again.

In preferences, proxy was set to auto (I don't have one), changed to no proxy and tried again. No changes.

Seems to be related to this issue: link