Radiator Issues

SMOD isn't an issue on that year, unless someone swapped in an old model radiator. You could always do the bypass for a bit if you want to rule it out.

Coolants can do some really weird stuff when you mix different 'versions'. They can harden up, look like corrosion, turn to jelly, form little tiny boba tea like balls, etc etc. If someone just grabbed whatever coolant was at the auto-parts store, you might be having issues with compatibility.
I personally would drain it and refill with just water and run it like that for awhile, then put in the proper coolant. Maybe even cycle through a couple fills of water to make sure its flushed everything out.

There are also chemical test kits that will check coolant for head gasket leaks, but I've never messes with them.

And Yeah, I'm not seeing the "video below" either.