Thanks for sharing the main.log, @blcf!
So it looks like there is an rsync error occuring:
[terminalExec] Error: rsync error: some files/attrs were not transferred (see previous errors) (code 23)
That means somewhere in you transfer, there is a “chunk” that returned an error. Usually, this is at the very beginning of the transfer.
Can you try deleting your main.log files then starting the transfer again? Try copying the main.log and main.log.old before the transfer hits about 20%.
Right now the exact error is just cut off in the logs since there is so much data. Here’s an example of the sort of error this will be: Unable to pull a Kinsta site now - #3 by Kevin
Sometimes it’s just a corrupted file.