Yogurt turned out "slimy"

I've made several previous batches with with freeze dried cultures or backslopping and using skim to whole milk and had good success. This time not so much.

I used 2L of 1% milk with an Instant Pot and this starter:

https://bacillusbulgaricus.com/product/yogurt-starter/

I used the IP yogurt boil setting, let it cool. Added the preportioned sachets and then let it do its thing for 24 hours

When I went to move it to containers, it wasn't thick like the expected consistency nor was it runny like it didn't set up. It would flow off the ladle almost like a runny white glue.

The flavour is also very mild, which I understood the Bulgarian styles would have more tang, similar to the store bought Balkan styles.

The only thing I can think of that was different this time, was I ducked into town while things were cooling and the milk was below 100F when I added the starter.

Even after being refrigerated for several hours initally it hadn't firmed up.