Plugin causing invalid amp (Failed to parse JSON-LD data)

Hi

i Used the plugin for about a month, it’s working correctly however I noticed that now indexed pages on my webmaster console is decreasing day by day till I only got 4 valid pages out of 76

using fetch pages , webmaster tool and screaming frog gave an error Failed to parse JSON-LD data for all pages, the rest URL which previously already indexed are now goes into category Indexed, not submitted in sitemap and doesn’t perform well in serp

If we click on URL detail, there no additional information(mark up error or something like that)