Users with read only access cannot check to what customer the item tracing leads to, this action would need a read privilege as well as the write privilege, this is informative information that does require any changes.

The same issue has been seen on Vendor records too.

As a workaround:

Create a user with custom role depending on your company needs.

Select the table needed.

Add privileges such as READ/WRITE/etc.

Publish the roles and privileges and then test using them.