I have same issue. I choose "manual" update, then select "9.0.2" and download begins. When WP1 reboots, it begins decompressing, but after that, it shows some error related to file IMG not found or similar. In the download page, LibreElec wrote:
Warning: Update at WP1 is broken if you use img.gz – please use .tar to update
So it seems we need to download the .tar file and update from SD card, as before. But my question is, will I forget my LibreElec configuration (tvheadend config, plugins, storage paths ...)??