Remove the password protection prior to uploading it to them, perhaps? Follow this
tutorial from adobe if you're not familiar with it. Alternatively [though I think it'll raise more issue and allow them to reject the data because it's been through an image processor] open them through Photoshop and re-publish it in PDF. I believe it will remove the password protection, as well? Just... try number one first.
seems kind of counterproductive for the case…password was clearly in title. this is absolutely absurd.
Be that as it may, if it helps resolving this way too long case, isn't it worth trying?
Maybe your email was forwarded to the security division through their internal system that removed the subject you originally wrote and replaced it with your stake ID or other format according to their SOP, or they simply probably missed the fact that the password was there on the subject and too proud to admit it, or maybe there are other reason, whatever that is. If providing another document, that minimize whatever possible risk of inaccessibility, helps put this headache to rest, I think it's worth doing.