Some files are not getting backed up

I noticed that some of my files are not getting backed up.
They have a blue mark.
These are files that i havent even touched in a while. Some are Excel files and some pdf. Why do some not get backed up??? On my dashboard it also says last backup was in March but in the cloud backup screen it says it just took place recently. Weird.

and will this setting fix that? i attached a file.

Product & version number: Norton 360 deluxe.

OS details:windows 10

If you have any supporting screenshots, please add them:

fwiw ~ I run Back up common file types only = disabled