Timeshift backing up excluded folders anyway

So, after having solved my issue with not being able to boot my OS by flashing my BIOS, I figured I would look into setting up Timeshift. Just in case. I know it has nothing to do with BIOS, but if I ever have to reinstall my OS, it would be nice to be able to just restore a snapshot to get back to where I was.

Now, I have a 1.3 TB HDD in my HTPC and also an 18TB network drive. Both of these are mapped to folders in my ~/. I have both of these folders excluded in Timeshift filters because they're far too big to back up. However, despite being excluded, when I sit here and watch Timeshift create a snapshot, it still goes about syncing files in the excluded mapped network folder to the NAS. On top of that, I can hear the HDDs in my NAS in the other room go to work when Timeshift reaches that point and begins to sync them.

How do I stop this? It's not supposed to be backing that up. I have it excluded. It says in the summary that patterns matching my ~/network/mount/point will be excluded.