welcome to the forum,
roundsync has not been updated since Sep 10, 2024 and it is not a fork of rclone.
fwiw, i run rclone natively on android.
i have a handy, dandy howto guide
https://forum.rclone.org/t/rclone-on-termux-turn-your-android-phone-into-a-media-server/16064
maybe try the following
- re-run the commands with
-vvfor debug output - pick one single file to focus on.
- on the source file and on the dest file,
runrclone lsf --format=psth - post the output