Occasional problems uploading images
Firefox 75.0 FWIW.
POST to newattachment.php occasionally yields an SSL_ERROR_BAD_MAC_ALERT. Upload window says "Uploading File(s) - Please Wait", failing silently.
May need to update your SSL certs, may be non-SSL related entirely if erroring server-side. Can't know without seeing the logs. Time this happened: 8:50 ish EST so you might see something then.