Burning DVD fails to copy all files

I recently purchased a Pioneer BDR XD07TS (Blu-ray/DVD/CD writer) to back-up 20 years of photos. However, after 10 different attempts to burn a DVD with 2,860 files (3.21GB) a random number of around 300 files fail to copy. Each time I burn, different files that fail to burn. There is no alert that that files have failed to copy. The verification step does not alert to any problems either.

So all look s okay, until I painfully compare the Burn file on the Mac, with what was actually burned on the DVD.

I have tried different discs with no improvement.

I am trying to figure out whether this is a OS issue, disc issue or drive issue. Has anyone else encountered this problem or have any advice?

Currently using Catalina on iMac (late 2012).