VPXA had been restarted, result is the same. I also tried to disconnected the ESXi host from vCenter and trying backup from ESXi host dirtectly the result is the same.
I have a new vSphere 7.0U1 farm and new Nakivo server setup. I tried to backup VM on ESXI host, I got the following error message. All backup jobs got the same error. Local reseller already helped to upgrade Nakivo to 10.1.1 (build 49573 from 2020 Nov Sat at 12:11:00 PM) but the result is still same. VMware vSphere Storage API error has occurred on the "Onboard transporter" transporter.