How to show related nodes in a view block based on taxonomy terms?
SOLVED


Add a Contextual Filter->Has Taxonomy Term ID
When the filter value is NOT available:


Provide default value Type: Taxonomy term ID from URL
Check only: Load default filter from node page, that's good for related taxonomy blocks; Limit terms by vocabulary; Vocabulary: my-vocabulary; Filter to items that share my term.

When the filter value IS available or default is provided:
Check only: Reduce duplicates.