Process/Decode Chunk Issue

I have some NetCDF UKCP data with a variable called "yyyymmdd" that is stored in the Kerchunk file like so:

"yyyymmdd/.zarray": "{\"chunks\":[1,64],\"compressor\":null,\"dtype\":\"|S1\",\"fill_value\":\"IA==\",\"filters\":null,\"order\":\"C\",\"shape\":[3600,64],\"zarr_format\":2}",
        "yyyymmdd/.zattrs": "{\"_ARRAY_DIMENSIONS\":[\"time\",\"string64\"],\"long_name\":\"yyyymmdd\",\"units\":\"1\"}",
        "yyyymmdd/0.0": "19801201",
        "yyyymmdd/1.0": "19801202",
        "yyyymmdd/2.0": "19801203",
        "yyyymmdd/3.0": "19801204",
        "yyyymmdd/4.0": "19801205",
        "yyyymmdd/5.0": "19801206",
        "yyyymmdd/6.0": "19801207",
        "yyyymmdd/7.0": "19801208",
        "yyyymmdd/8.0": "19801209",
        "yyyymmdd/9.0": "19801210",

When decoded I get the error message:
cannot reshape array of size 8 into shape (1,64)

Which I think is because the part of Zarr that decodes this is expecting a base64 encoded array rather than a string of 8 characters? That or the dimension/chunk/shape is being interpreted incorrectly. How should an array like this be interpreted within Zarr and decoded into an array of 1 by 64 when each chunk is an 8 character string?

Reproduce the failure using the supplied Kerchunk references and the yyyymmdd .zarray metadata. Trace how the chunk value is decoded and reshaped, then verify that the representation is interpreted consistently with the declared shape [3600,64] and chunk size [1,64], producing the expected 1-by-64 result.