Those kinds of errors usually occur when there is an AV or EDR solution is running on one of the servers. Disabling them is crucial for the process to run flawlessly.
If both servers are virtual machines, it may be quicker to simply re-attach the VHDX/VMDK file that is hosting your data and export/import network shares from/to Windows Registry. This approach takes minutes compared to SMS.
If old server is a physical one there is still an option to do as above virtualizing the existing physical disk using Microsoft Disk2VHD https://aka.ms/disk2vhd or free V2V Converter https://www.starwindsoftware.com/starwind-v2v-converter.