I have recently had a number of clients complaining of the same thing, ESET BPP not coming up when relevant sites are accessed, and i've just tested it myself and am seeing the same. It seems to have stopped working at some point last week. for both of us.
As a reseller, I'd like to be able to explain to my customers why this is happening. It is true for me across all browsers and apparently all sites, and BPP is even not displayed if I set a site to explicitly use it in the settings.