Big Sur's open command has changed and sometimes does odd things if the URL isn't pre-coded.
For example, in Big Sur, if you use:
open "tel:+44 123 456"
you get the output:
The file /Users/<removed>/tel:+44 123 456 does not exist.
Prior to Big Sur, you could throw anything at the open command and it would encode and open it, so the tel: url above would have opened Facetime and dialled the number.
The URLs you're generating aren't valid. You need to %-encode values inserted into URLs (e.g. the correct URL for input Profits $SNAP @ 41.89 △3.34% is kmtrigger://macro=johnyCinco%20Orig&value=Profits%20%24SNAP%20%40%2041.89%20%E2%96%B33.34%25), but Run Script doesn't support %-encoding.