Hi! I'm using a few attiny85 in my projects, programming them via the arduino IDE. A few days ago I started having trouble programming my newest batch of chips (Arduino and avrdude said invalid device id). After troubleshooting I found that all my programmable chips have the text "1323" on them, to the right of the Atmel logo, while the failing chips says "1404". I can't find anything about 1323 vs 1404 in the datasheet, so I'm reaching out here to see if anyone else knows more about this?
In short, my question is: what's the difference between 1323 and 1404 variants of attiny85? (Attached: picture of the two variants)