I sent it to support@featuredimagefromurl.com. Could you check your mailbox?
Thank you.
This problem happened again. Please tell me what data should I send to you.
Wordpress Version is 5.4.2, Featured Image from URL Version is 3.2.9.
Thank you for your reply, @marceljm.
Once I deactivate the plugin and activate it again, it looks like working rightly.
If this problem will happen again, I will report it to you.
Thanks for your support.