I installed MMM-Jast v2.9.5 on a fresh Install of MagicMirror2 on my Raspberry Pi 5.
All I was getting was the word “Loading”. The problem was fixed when I downgraded yahoo-finance2 from 2.14.0 to 2.11.3 as in the Jast package.json.

cd ~/MagicMirror/modules/MMM-Jast
rm -rf node_modules package-lock.json
npm install yahoo-finance2@2.11.3 --save-exact