opt-switch option does not parse value

opt-switch maxThreadFileBufferSize=1
/*---------------------------------------------------------------------------*\
| =========                 |                                                 |
| \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox           |
|  \\    /   O peration     | Version:  2107                                  |
|   \\  /    A nd           | Website:  www.openfoam.com                      |
|    \\/     M anipulation  |                                                 |
\*---------------------------------------------------------------------------*/
Build  : ad8e5540a3-20210929 OPENFOAM=2107 version=com
Arch   : "LSB;label=32;scalar=64"
Exec   : simpleFoam -parallel -fileHandler collated -opt-switch maxThreadFileBufferSize=5e9
Date   : Sep 29 2021
Time   : 17:43:09
Host   : linux-bymj
PID    : 26907
I/O    : collated [threaded] (maxThreadFileBufferSize = 1).
         Requires buffer large enough to collect all data or thread support
         enabled in MPI. If MPI thread support cannot be enabled, deactivate
         threading by setting maxThreadFileBufferSize to 0 in
         OpenFOAM etc/controlDict
Case   : /home/mattijs/OpenFOAM/OpenFOAM-plus/work/develop/openfoam/tutorials/incompressible/simpleFoam/pitzDaily
nProcs : 2
Hosts  :