After a little googling, it seems that the subdomain for backblaze got incorrectly added to a blacklist for many virus blocking programs back in 2018 and has been removed and readded multiple times since, due to general mass confusion about how it got there in the first place. Since I just use backblaze for image storage I have no control over which subdomain hosts, my photos just go on their servers and from there to you. :/ Soooooo... I have no idea how to fix that.