Had a SOBR offload job that had files locked when a second offload job wanted to use the same files.
Veeam suggested changing the offload job frequency using the reg key below:

By default the SOBR offload runs every 4 hours, please apply below registry key to change the offload frequency in Veeam backup server:
Key: SOBRArchivingScanPeriod
Type: REG_DWORD
Value: 8 (in hours) — ensure to select decimal
Path: HKLM\SOFTWARE\Veeam\Veeam Backup & Replication\
Description: The key is responsible for the interval of starting the SOBR Offload job. 

Please restart the Veeam backup server machine afterward.

Also had an issue with a backup chain that was syncing files to/from the azure repo, one of which is 6TB.
This large file caused a bunch of errors due to insufficient space in the system %temp% directory (c:\windows\temp\)

Solution is to set a custom temp directory (with sufficient space) on the backup server where the extents are connected (in this case, the backup proxy).

HKEY_LOCAL_MACHINE\SOFTWARE\Veeam\Veeam Backup and Replication\
Name: CustomTempDirPath
Type: REG_SZ
Value: should be system Variable for %Temp% by default. 

This let me direct Veeam to a temp folder with sufficient space.