laviniuc replied at 2019-06-22 13:47:20
1 month old phone, no root, no bootloader, no weird/suspicions apps installed (only most popular from google play store).
Also "used wifi to download, did not interrupt the download in any way, decrypt step went OK" + full battery.
Phone from official eu distribution, not from random ali seller (so at least I have a warranty, but I still have to wait until monday to do something)
Both previous updates (for 10.2.xxx) went smooth.