My website http://embedsysweekly.com is validated for the Summary Card with Large Image (As an instance this page http://embedsysweekly.com/issue10-system-on-chip-resistor-nand-tcp/)
When I share my page on Twitter the card works as expected but after some time my cards are no more displayed
For example these tweets :
Is there something wrong with the way I provide meta data or anything else?
Thank you for your help
PS : You could not that @nytimes tweets with cards have the same problem https://twitter.com/nytimes/status/417690018703220736