Some uploaded binary files fail to open

Some (maybe all) trx.mat files, once uploaded to https://nyx.pasteur.cloud/larvatagger, cannot be opened; larvatagger stays in an ever-loading state and displays the following message:

┌ Warning: error while processing received msg
│   exception =
│    unable to determine if /app/storage/exports/f9027a82df1499833d79d13d8e18be7b/larvatagger/trx_small.mat is accessible in the HDF5 format (file may not exist)
│    Stacktrace:
│      [1] error(s::String)
│        @ Base ./error.jl:35
│      [2] h5open(filename::String, mode::String, fapl::HDF5.FileAccessProperties, fcpl::HDF5.FileCreateProperties; swmr::Bool)
│        @ HDF5 /app/julia/packages/HDF5/Z859u/src/file.jl:48
...
│      [8] h5open
│        @ /app/julia/packages/HDF5/Z859u/src/file.jl:94 [inlined]
│      [9] checktrxmat
│        @ /app/julia/packages/PlanarLarvae/rfGyZ/src/Trxmat.jl:190 [inlined]
...

The same files can be successfully loaded from disk in their native form.