Time machine freezes up after several backups to external drive.

I am running Big Sur on a 2016, 16 inch, 2 TB MacBook Pro that is using less than 1 TB of storage. I bought a SanDisk 2TB solid state hard drive. It is connected with a USB C cable at both ends. I have made five Tim Machine backups. The 6th backup froze up when attempting to backup. Subsequent attempts to backup freeze at the same point. Does anybody have a suggestion to help resolve to resolve this problem?

I have repaired the disk and erased the disk using the disk utility multiple times and end up with the same problem. Sometime it is the second backup and sometime a few backups later. I happens even if I have not ejected the disk from my computer.

I bought the SanDisk after my Airport Time Capsule gave out on me.