After the latest update, a permanent redownload of the game occurs when you turn off Uplay and turn it on!
Additionally, it downloads 8GB once and 11GB later. Fix it! It is impossible to start the game and play!
I noticed that others also have this problem:
https://www.reddit.com/r/Rainbow6/comments/pk8yq0/have_to_download_r6s_latest_patch_every_time_i/