Why did my poolish fail?

Hi I’m new here i have a question regarding added this: poolish recipe to Neapolitan style dough:

300ML water
300g 00 flour
6g yeast

After 1 hour room temp
then in fridge for 16 hours overnight
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I did all this my fridge is on ‘3’. in the UK. Its not so cold not so warm. I left it overnight.

When i added it to my dough which was:
For Dough
220g 00 flour
22g 0 flour
61g polish
1g yeast
1tsp salt
—

The poolish didn’t seem it rose much and it was gloopy as hell. Anyway when i cooked the pizza it seemed ok but
was way undercooked (due to the poolish not rising).

My question is why put it in the fridge in the first place? The last time i made some was with mother yeast but this takes
over 3 days to get a rise. This worked like a charm. Any help would be cool!