it depends on the build.  USE_ZLIB_CRC32 causes it due to zlib's 32-bitness as noted my marko.

$ ./python 
Python 3.11.0a6+ (heads/main-dirty:b3f2d4c8ba, Mar 19 2022, 15:32:04) [GCC 9.4.0] on linux
Type "help", "copyright", "credits" or "license" for more information.
>>> import binascii, zlib
>>> bigdata=memoryview(bytearray((1<<32) + 100))
>>> 
>>> print(binascii.crc32(bigdata))
2575877834
>>> crc = binascii.crc32(bigdata[:1000])
>>> crc = binascii.crc32(bigdata[1000:], crc)
>>> print(crc)
2838121701
>>> 
>>> print(zlib.crc32(bigdata))
2838121701
>>> crc = zlib.crc32(bigdata[:1000])
>>> crc = zlib.crc32(bigdata[1000:], crc)
>>> print(crc)
2838121701
>>>