I had similar problem, and went through a very hard time. I have disabled the multiple languages input, still and with disnoted issue comes, hard reboot and comes with no pattern traced. I make a clean macOS Catalina installation with delete partition, download from web the latest version, etc. While installing it, the fan span crazy and all seems very slow, which I noticed the language input icon was there and gave me PKDownloadError error 8, every trial. under recovery, I even had to make a hard reboot! I also could not restored back the original macOS that comes with my MacBook Air, which was Mojave. Luckily, I had another MacBook, which I had to make a bootable USB with Mojave, then put in fresh boot and installation from the USB. After install Mojave clean, I then go for Catalina. Then only other applications. Till date, so far so good, none of these two happened. more than three weeks already. Hope my horror experience helps.