I am currently designing a board using the STM32MP153FAC TFBGA361 Layout. I have divided the chip into 5 different sub-symbols in my design. When I run the ERC I am getting 4 identical errors: Error:Symbol 'STM32MP153FAC1' has multiple pins with the same pin number {Symbol IC2 [STM32MP132MP153FAC1]}. I have double, triple and quadruple checked all of the symbols and found nothing that is in fact duplicated. I have also carefully checked the pin sheet and found no duplicates, though I do have multiple pins with the same name.
I would love if someone had some insight on this, or could direct me as to whether this should in fact be sent as a bug report. If it would help to give the library file for the symbols I can probably figure out how to do that as well.
Can you post a small example project in which this custom symbol is used. This allows us to run ERC and also load it in the symbol editor to see what is going on. I have not updated to KiCad V9 yet myself, but there are plenty other forum users who have and also can have a look at your symbol.