We have added a new optimized script for conditional fields. Please make sure you clear the cache. And if problem not solved you can revert back to legacy conditional from WooCommerce -> Settings -> PPOM Settings -> Enable legacy Conditional Logic Script (before v20.1)
Enabling Legacy Conditional Logic fixed the issue.
Does this mean, if I want to use the NEW conditional logic code, I need to redesign all meta conditions and delete the old ones?