This has been addressed in several previous threads. Basically the gist of it is, there is no guarantee (or even the faintest assumption) that when a new backup job starts, Duplicati will scan through the files that have already been successfully backed up and account for them in the “size remaining” indicator. It will, however, still skip them once it reaches that point in the backup run, whenever that may be. The only way to know for sure is to watch the Information logs as they go by and see what’s being backed up or skipped. Or do what I did and backup a smaller set at first, wait until it’s done, add more, and so on.
As an aside: did you only pause your backup job before restarting, instead of actually stopping your backup job? That worries me slightly, as stopping it would ensure it resolves the open database entries and such correctly. I’m not 100% sure what the effect of restarting with the backup job merely paused would be (hopefully nothing), but in the future if you need to interrupt a backup job I’d recommend just stopping it. However if your current backup operation isn’t actually giving you errors, then I’d guess you’re OK.