I reported the issue to Every.org and received this reply:
Hi Avi,
Thank you so much for your generosity and participating in the #FallGivingChallenge!
Due to the sudden high volume, PayPal seems to be holding our transactions and your donations are currently stuck in “pending” for us. We are investigating the issue and will let you know when we have an update.
The match will be applied after the PayPal donation is cleared and you will receive a receipt then. We will make sure you receive both the $100 and $10 match for sharing for your first donation to Centre for Effective Altruism USA.
Thank you for the detailed feedback: we are making a change to issue receipts for PayPal donations immediately to reduce confusion.
We apologize for any inconvenience and thank you once again for using Every.org!
I reported the issue to Every.org and received this reply: