Welp, you’re not the only one.
First, there’s no V1.2 that I know of.
Your V1.1 is similar to X1.2, so if you were looking at X1.1 pinout on wiki and thinking that it’s correct for you — well, it’s not… Try actually referring to X1.2 pinout instead.
So, pins 3 and 5 on your V1.1 are, in fact, I2C8_M2. That said, there’s one more issue: the schematics available for download (and the info on wiki) is wrong, as there’s pull up on SCL but NOT on SDA for I2C8.