Make sure previous attempts at restoring are not 'pending'.
Moodle version of old server? Moodle version on new server?
Moosh command you've shown tries to import the backup in course category 1. Uhhh .... you do have a course category 1 already in existence, correct?
On old server, make the backup again and this time, exclude any duplicated activities (if you can re-call which ones were dups). When you have an opportunity to name the backup file insert something like -nda- (no duplicated activities).
++ Did you remember to make the first column something unique in your call to get_records? Duplicate value ' myoldmoodleserver.co+190131100650+4F4fV1 myoldmoodleserver.co+190131100650+mANZOW' found in column 'concat(stamp, ' ', version)'. ++
This error is pointing (I think) to the backup file itself.
Could also try making 2 backups of same course ... 1st one about 1/2 of activities. Named appropriately. That should reduce the size of the backups. Restore the first as normal, then restore the second into first course restored.